Exhibit 10.1


 


Execution Copy


 


STOCK PURCHASE AGREEMENT


 


This Stock Purchase Agreement (“Agreement”)
is made as of July 12, 2018 (the “Effective Date”), by and between ClearSign Combustion Corporation, a Washington
corporation (the “Company”), and CLIRSPV, LLC, a Delaware limited liability company (the “Purchaser”).


 


AGREEMENT


 


NOW, THEREFORE, IN CONSIDERATION of
the mutual covenants contained in this Agreement, and for other good and valuable consideration, the receipt and adequacy of which
are hereby acknowledged, the Company and the Purchaser agree as follows:


 


SECTION 1.


AUTHORIZATION OF SALE OF STOCK


 


The Company has authorized the sale and
issuance of 5,213,543 shares (the “Shares”) of its Common Stock, par value $0.0001 per share (the “Common
Stock”), on the terms and subject to the conditions set forth in this Agreement.


 


SECTION 2.


AGREEMENT TO SELL AND PURCHASE THE STOCK


 


2.1        
Sale of Stock.  At the Closing (as defined in Section 3.1), the Company will sell to the Purchaser, and
the Purchaser will purchase from the Company, the Shares at a purchase price of $2.25 per Share for an aggregate purchase price
of $11,730,471.75.


 


SECTION 3.


CLOSING AND DELIVERY


 


3.1        
Closing.  The closing of the purchase and sale of the Shares pursuant to this Agreement (the “Closing”)
shall be held on July 20, 2018 or on such other date and place as may be agreed to by the Company and the Purchaser and shall take
place by the electronic delivery of documents.  At or prior to the Closing, the Purchaser shall execute any related agreements
or other documents required to be executed hereunder, dated as of the date of the Closing (the “Closing Date”).


 


3.2        
Issuance of the Shares at the Closing.  At the Closing, the Company shall issue or deliver to the Purchaser
evidence of a book entry position evidencing the Shares purchased by the Purchaser hereunder, registered in the name of the Purchaser,
or in such nominee name(s) as designated by the Purchaser, representing the number of Shares to be purchased by the Purchaser
at the Closing against payment of the purchase price for such Shares.  The name in which the shares are to be issued to the
Purchaser are set forth in the Purchaser Questionnaire in the form attached hereto as Appendix I (the “Purchaser Questionnaire”),
as completed by the Purchaser, which shall be provided to the Company prior to the Closing Date.


 


3.3        
Delivery of the Registration Rights Agreement.  At the Closing, the Company and the Purchaser shall execute
and deliver the Registration Rights Agreement in the form attached hereto as Appendix II (the “Registration Rights Agreement”),
with respect to the registration of the Shares and any Additional Shares under the Securities Act of 1933, as amended (the “Securities
Act”).


 


3.4        
Delivery of the Voting Agreement.  At the Closing, the Company and the Purchaser shall execute and deliver the
Voting Agreement in the form attached hereto as Appendix III (the “Voting Agreement”).


 




    	 



     


    

 


Execution Copy 


 


SECTION 4.


REPRESENTATIONS, WARRANTIES AND COVENANTS
OF THE COMPANY


 


Except as set forth on the Schedule of Exceptions
delivered to the Purchaser concurrently with the execution of this Agreement (the “Schedule of Exceptions”)
or, solely with respect to Sections 4.1, 4.6 (excluding the 7th sentence thereof), 4.10, 4.14, 4.15, 4.18, 4.19, 4.23, 4.25,
4.26, 4.29, 4.30 and 4.34, as otherwise described in the SEC Documents (as defined below), which disclosures qualify these representations
and warranties in their entirety, the Company hereby represents and warrants as of the date hereof to, and covenants with, the
Purchaser as follows:


 


4.1        
Subsidiaries.  The Company has no direct or indirect Subsidiaries (as defined below) other than those listed
in Exhibit 21 to the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. The Company
owns, directly or indirectly, all of the capital stock or comparable equity interests of each Subsidiary free and clear of any
and all liens, charges, claims, encumbrances, security interests, rights of first refusal, preemptive rights or other restrictions
of any kind (collectively, “Liens”), and all the issued and outstanding shares of capital stock or comparable
equity interest of each Subsidiary are validly issued and are fully paid, non-assessable and free of preemptive and similar rights
to subscribe for or purchase securities.  “Subsidiary” means any entity in which the Company, directly
or indirectly, owns sufficient capital stock or holds a sufficient equity or similar interest such that it is consolidated with
the Company in the financial statements of the Company.


 


4.2        
Organization and Standing.  The Company and each of its Subsidiaries (i) has been duly incorporated and
is validly existing as a corporation in good standing under the laws of the jurisdiction of its incorporation or organization (as
applicable), with full corporate power and authority to own or lease, as the case may be, and to operate its properties and conduct
its business as presently conducted, and (ii) is duly qualified to do business as a foreign corporation and is in good standing
under the laws of each jurisdiction which requires such qualification, except in the case of clause (ii) above, to the extent
that the failure to be so qualified or be in good standing would not reasonably be expected to result in (i) a material adverse
effect on the validity or enforceability of this Agreement, (ii)  a material adverse effect on the condition (financial or
otherwise), earnings, business, results of operations, assets or properties of the Company and its Subsidiaries, taken as a whole,
or (iii) a material adverse effect on the Company’s ability to perform in any material respect its obligations under
this Agreement (any of (i), (ii) or (iii)) (a “Material Adverse Effect”).


  


4.3        
Corporate Power; Authorization.  The Company has all requisite corporate power and authority, and has taken
all requisite corporate action, to execute and deliver this Agreement, the Registration Rights Agreement and the Voting Agreement
(collectively, the “Transaction Documents”), sell and issue the Shares and Additional Shares and carry out and
perform all of its obligations under the Transaction Documents.  Each Transaction Document constitutes the legal, valid and
binding obligation of the Company, enforceable in accordance with its terms, except (i) as limited by applicable bankruptcy,
insolvency, reorganization, moratorium or similar laws relating to or affecting the enforcement of creditors’ rights generally,
(ii) as limited by equitable principles generally, including any specific performance and (iii) with respect to the Registration
Rights Agreement, as rights to indemnity or contribution may be limited by state or federal laws or public policy underlying such
laws.


 


4.4        
Issuance and Delivery of the Shares.  The Shares and Additional Shares have been duly authorized and, when issued
and paid for in compliance with the provisions of this Agreement, will be validly issued, fully paid and nonassessable and free
and clear of all Liens, other than restrictions on transfer imposed by applicable securities laws, and shall not be subject to
preemptive or similar rights.  Assuming the accuracy of the representations made by the Purchaser in Section 5, the offer
and issuance by the Company of the Shares and Additional Shares is exempt from registration under the Securities Act.


 




    	 



     


    

 


Execution Copy


 


4.5        
SEC Documents; Financial Statements.  The Company has filed in a timely manner all documents that the Company
was required to file with the Securities and Exchange Commission (the “Commission”) under Sections 13, 14(a) and
15(d) the Securities Exchange Act of 1934, as amended (the “Exchange Act”), since January 1, 2016
(collectively with all exhibits, schedules and annexes thereto, the “SEC Documents”).  As of their respective
filing dates (or, if amended prior to the date of this Agreement, when amended), all SEC Documents complied in all material respects
with the requirements of the Exchange Act and the rules and regulations of the Commission promulgated thereunder.  None
of the SEC Documents as of their respective dates contained any untrue statement of material fact or omitted to state a material
fact required to be stated therein or necessary to make the statements made therein, in light of the circumstances under which
they were made, not misleading.  The consolidated financial statements of the Company included in the SEC Documents (the “Financial
Statements”) present fairly the consolidated financial condition, results of operations and cash flows of the Company
and its Subsidiaries, taken as a whole, as of the dates and for the periods indicated, comply in all material respects with applicable
accounting requirements and the rules and regulations of the Commission with respect thereto as in effect at the time of filing
and have been prepared in conformity with generally accepted accounting principles (“GAAP”) applied on a consistent
basis throughout the periods involved (except as otherwise noted therein). Gumbiner Savett Inc., who have audited certain financial
statements of the Company, delivered their report with respect to the audited consolidated financial statements and schedules included
in the SEC Documents, are independent public accountants with respect to the Company within the meaning of the Exchange Act and
the applicable published rules and regulations thereunder.  There is no transaction, arrangement, or other relationship
between the Company (or any Subsidiary) and any unconsolidated or other off balance sheet entity that is required to be disclosed
by the Company in its Exchange Act filings that is not so disclosed.


  


4.6        
Capitalization.  The authorized capital stock of the Company consists of 62,000,000 shares of Common Stock and
2,000,000 shares of undesignated Preferred Stock.  As of the Effective Date, there are no shares of Preferred Stock issued
and outstanding and there are 21,417,909 shares of Common Stock issued and outstanding, of which no shares are owned by the Company. 
There are no other shares of any other class or series of capital stock of the Company issued or outstanding.  The Company
has no capital stock reserved for issuance, except that, as of March 31, 2018, there were (i) 1,185,256 shares of Common Stock
reserved for issuance pursuant to the Company’s 2011 Equity Incentive Plan, of which 969,384 shares are issuable upon the
exercise of stock options outstanding on March 31, 2018, (ii) 116,883 shares of Common Stock reserved for issuance pursuant
to the Company’s 2013 Consultant Stock Plan and 2,495,784 Warrants outstanding, including Warrants for the purchase of 2,395,471
shares of Common Stock with an exercise price of $4.00 per share, Warrants for the purchase of 80,000 shares of Common Stock with
an exercise price of $1.80 per share and a Warrant for the purchase of 20,313 shares of Common Stock with an exercise price of
$10.00 per share.  There are no bonds, debentures, notes or other indebtedness having general voting rights (or convertible
into securities having such rights) (“Voting Debt”) of the Company issued and outstanding.  Except as stated
above and included in Schedule 4.6, there are no existing options, warrants, calls, subscriptions or other rights, agreements,
arrangements or commitments relating to the issued or unissued capital stock of the Company, obligating the Company to issue, transfer,
sell, redeem, purchase, repurchase or otherwise acquire or cause to be issued, transferred, sold, redeemed, purchased, repurchased
or otherwise acquired any capital stock or Voting Debt of, or other equity interest in, the Company or securities or rights convertible
into or exchangeable for such shares or equity interests or obligations of the Company to grant, extend or enter into any such
option, warrant, call, subscription or other right, agreement, arrangement or commitment.  The issuance of Common Stock and
the grant of stock purchase pursuant to any provision of this Agreement will not give rise to any preemptive rights or rights of
first refusal on behalf of any Person (as defined below) or result in the triggering of any anti-dilution or price adjustment rights. 
There are no agreements or arrangements under which the Company or any of its Subsidiaries is obligated to register the sale of
any of their securities under the Securities Act.  “Person” means an individual, corporation, partnership,
limited liability company, trust, business trust, association, joint stock company, joint venture, sole proprietorship, unincorporated
organization, governmental authority or any other form of entity not specifically listed herein.


 


4.7        
Litigation.  No action, suit or proceeding by or before any court or governmental agency, authority or body
or any arbitrator involving the Company or any of its Subsidiaries or their respective properties is pending or, to the best knowledge
of the Company, threatened that would have or reasonably be expected to have, individually or in the aggregate, a Material Adverse
Effect, whether or not arising from transactions in the ordinary course of business.  Neither the Company nor any Subsidiary,
nor to the Company’s knowledge any director or officer thereof, is or has been the subject of any action, suit or proceeding
involving a claim of violation of or liability under federal or state securities laws or a claim of breach of fiduciary duty. 
There has not been, and to the Company’s knowledge there is not pending or contemplated, any investigation by the Commission
involving the Company or, to the Company’s knowledge, any current or former director or officer of the Company.  The
Commission has not issued any stop order or other order suspending the effectiveness of any registration statement filed by the
Company or any of its Subsidiaries under the Exchange Act or the Securities Act.  There are no outstanding orders, judgments,
injunctions, awards or decrees of any court, arbitrator or governmental or regulatory body against the Company or, to the Company’s
knowledge, any executive officers or directors of the Company in their capacities as such, which individually or in the aggregate,
would reasonably be expected to have a Material Adverse Effect.


  




    	 



     


    

 


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4.8        
Governmental Consents.  No consent, approval, order or authorization of, or registration, qualification, designation,
declaration or filing with, any federal, state, or local governmental authority on the part of the Company or any of its Subsidiaries
is required in connection with the consummation of the transactions contemplated by the Transaction Documents except for (a) the
filing of a Form D with the Commission under the Securities Act and compliance with the securities and blue sky laws in the
states and other jurisdictions in which shares of Common Stock are offered and/or sold, which compliance will be effected in accordance
with such laws, (b) the filing of a Notification Form: Listing of Additional Shares with The Nasdaq Stock Market (“NASDAQ”)
for the listing of the Shares (which has been made and must be approved prior to the Closing) and (c) the filing of one or
more registration statements and all amendments thereto with the Commission as contemplated by the Registration Rights Agreement.


 


4.9        
No Default or Consents.  Neither the execution, delivery or performance of the Transaction Documents by the
Company nor the consummation of any of the transactions contemplated thereby (including, without limitation, the issuance and sale
by the Company of the Shares or the Additional Shares) will conflict with, result in a breach or violation of, or imposition of
any lien, charge or encumbrance upon any property or assets of the Company pursuant to, (i) the charter or by-laws of the
Company or any of its Subsidiaries, (ii) the terms of any indenture, contract, lease, mortgage, deed of trust, note agreement,
loan agreement or other agreement, obligation, condition, covenant or instrument to which the Company or any of its Subsidiaries
is a party or bound or to which its or their property is subject, or (iii)  any statute, law, rule, regulation, judgment,
order or decree applicable to the Company or any of its Subsidiaries of any court, regulatory body, administrative agency, governmental
body, arbitrator or other authority having jurisdiction over the Company or any of its Subsidiaries or any of their respective
properties, except in the case of clauses (ii) and (iii) above, for any conflict, breach or violation of, or imposition
that would not, individually or in the aggregate, have or reasonably be expected to have a Material Adverse Effect.


 


4.10      No
Material Adverse Change.  Since March 31, 2018, (i) there have not been any changes in the authorized capital,
assets, liabilities, financial condition, business, Material Contracts (as defined below) or operations of the Company from that
reflected in the Financial Statements except changes in the ordinary course of business which have not had or would not reasonably
be expected to have, either individually or in the aggregate, a Material Adverse Effect, (ii) the Company has not incurred
any material liabilities (contingent or otherwise) other than (A) trade payables, accrued expenses and other liabilities incurred
in the ordinary course of business consistent with past practice and (B) liabilities not required to be reflected in the Company’s
financial statements pursuant to GAAP or required to be disclosed in filings made with the Commission, (iii) the Company has
not altered materially its method of accounting or the manner in which it keeps its accounting books and records, (iv) the
Company has not declared or made any dividend or distribution of cash or other property to its shareholders or purchased, redeemed
or made any agreements to purchase or redeem any shares of its capital stock, and (v) the Company has not issued any equity
securities to any officer, director or Affiliate (as defined below), except Common Stock issued pursuant to existing Company stock
option or stock purchase plans or executive and director arrangements disclosed in the SEC Documents.  Neither the Company
nor any of its Subsidiaries has taken any steps to seek protection pursuant to any law or statute relating to bankruptcy, insolvency,
reorganization, receivership, liquidation or winding up, nor does the Company or any Subsidiary have any knowledge or reason to
believe that any of their respective creditors intend to initiate involuntary bankruptcy proceedings or any actual knowledge of
any fact which would reasonably lead a creditor to do so. The Company and its Subsidiaries, individually and on a consolidated
basis, are not as of the date hereof, and after giving effect to the transactions contemplated hereby to occur at the Closing,
will not be insolvent.  Neither the Company nor any of its Subsidiaries has engaged in any business or in any transaction,
and is not about to engage in any business or in any transaction, for which the Company’s or such Subsidiary’s remaining
assets constitute unreasonably small capital.  For purposes of this Agreement, “Affiliate” shall have the same
meaning ascribed to such term in the Voting Agreement.


 


4.11      No
General Solicitation.  Neither the Company nor any Person acting on its behalf, has engaged in any form of general
solicitation or general advertising (within the meaning of Regulation D promulgated under the Securities Act) in connection with
the offer or sale of the Shares.


 




    	 



     


    

 


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4.12      No
Integrated Offering.  Neither of the Company or any Person acting on its behalf has, directly or indirectly, made
any offers or sales of any security or solicited any offers to buy any Company security, under circumstances that would adversely
affect reliance by the Company on Section 4(a)(2) of the Securities Act or require registration of any of the Shares
or any Additional Shares under the Securities Act or cause this offering of the Shares and Additional Shares to be integrated with
prior offerings by the Company (i) for purposes of the Securities Act or (ii) for purposes of the rules and regulations
of NASDAQ such that it would require stockholder approval prior to the Closing.


 


4.13      Sarbanes-Oxley
Act.  There is and has been no failure on the part of the Company and, to the knowledge of the Company, any of the
Company’s directors or officers, in their capacities as such, to comply with any applicable provision of the Sarbanes-Oxley
Act of 2002 and the rules and regulations promulgated in connection therewith, including, without limitation, Section 402
relating to loans.


 


4.14      Intellectual
Property.  The Company and its Subsidiaries collectively own, possess, license or have other rights to use, on reasonable
terms, all patents, patent applications, trade and service marks, trade and service mark registrations, trade names, copyrights,
licenses, inventions, trade secrets, technology, know-how and other intellectual property (collectively, the “Intellectual
Property”) necessary for the conduct of the Company’s and its Subsidiaries’ business, taken as a whole, as
now conducted or as proposed in the SEC Documents to be conducted (the “Company Intellectual Property”). To
the knowledge of the Company, there are no rights of third parties to any Company Intellectual Property, other than as licensed
by the Company. To the knowledge of the Company, there is no infringement by third parties of any Company Intellectual Property.
There is no pending or, to the Company’s knowledge, threatened action, suit, proceeding or claim by others challenging the
Company’s rights in or to any Company Intellectual Property. There is no pending or, to the Company’s knowledge, threatened
action, suit, proceeding or claim by others challenging the validity or scope of any Company Intellectual Property. There is no
pending or, to the Company’s knowledge, threatened action, suit, proceeding or claim by others that the Company infringes
or otherwise violates any patent, trademark, copyright, trade secret or other proprietary rights of others. The Company is not
aware of any facts required to be disclosed to the U.S. Patent and Trademark Office (“USPTO”) which have not
been disclosed to the USPTO and which would preclude the grant of a patent in connection with any patent application of the Company
Intellectual Property or could form the basis of a finding of invalidity with respect to any issued patents of the Company Intellectual
Property.  The Company and its Subsidiaries collectively have taken reasonable security measures to protect the secrecy, confidentiality
and value of all of the Company Intellectual Property, except where the failure to do so would not, individually or in the aggregate,
have or reasonably be expected to have a Material Adverse Effect.


 


4.15      Compliance
with NASDAQ Continued Listing Requirements.  The Company’s Common Stock is registered pursuant to Section 12(b) of
the Exchange Act, and the Company has taken no action designed to terminate the registration of the Common Stock under the Exchange
Act nor has the Company received any notification that the Commission is contemplating terminating such registration. The Company
is in compliance with applicable NASDAQ continued listing requirements. There are no proceedings pending or, to the Company’s
knowledge, threatened against the Company relating to the continued listing of the Common Stock on NASDAQ and the Company has not
received any notice of, nor to the Company’s knowledge is there any reasonable basis for, the delisting of the Common Stock
from NASDAQ.


 


4.16      Disclosure. 
The Company understands and confirms that the Purchaser will rely on the foregoing representations in effecting transactions in
securities of the Company.  To the knowledge of the executive officers of the Company, all due diligence materials regarding
the Company, its business and the transactions contemplated hereby, furnished by or on behalf of the Company to the Purchaser upon
its request are, when taken together with the SEC Documents and the Schedule of Exceptions, true and correct in all material respects
and do not contain any untrue statement of a material fact or omit to state any material fact necessary in order to make the statements
made therein, in light of the circumstances under which they were made, not misleading.


 


4.17      Contracts. 
Each franchise, contract or other document of a character required to be described in the SEC Documents or to be filed as an exhibit
to the SEC Documents under the Securities Act and the rules and regulations promulgated thereunder (collectively, the “Material
Contracts”) is so described or filed.  Neither the Company nor any of its Subsidiaries is in default under or in
violation of (and to the Company’s knowledge no event has occurred that has not been waived that, with notice or lapse of
time or both, would result in a default by the Company or any of its Subsidiaries under), nor has the Company or any of its Subsidiaries
received written notice of a claim that it is in default under or that it is in violation of, any Material Contract (whether or
not such default or violation has been waived).


 




    	 



     


    

 


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4.18      Properties
and Assets.  The Company and its Subsidiaries have good and marketable title to all real property and tangible personal
property owned by them which is material to the business of the Company and its Subsidiaries, taken as a whole, in each case free
and clear of all Liens except such as do not materially affect the value of such property or do not materially interfere with the
use made and proposed to be made of such property by the Company and any of its Subsidiaries or relate to indebtedness of the Company
in existence as of the Effective Date. Except as would not have or reasonably be expected to have, individually or in the aggregate,
a Material Adverse Effect, any real property and facilities held under lease by the Company and any of its Subsidiaries are held
by them under valid, subsisting and enforceable leases.


 


4.19      Compliance. 
Except as (A) set forth herein or (B) would not (1) have or reasonably be expected to have, individually or in the
aggregate, a Material Adverse Effect or (2) materially and adversely affect the validity or enforceability of, or the authority
or the ability of the Company to perform its obligations under, the Transaction Documents: (i)  the Company and each of its
Subsidiaries are in compliance with statutes, laws, ordinances, rules and regulations applicable to the Company and its Subsidiaries
(collectively, “Applicable Laws”); (ii)  the Company and each of its Subsidiaries possess all licenses,
certificates, approvals, authorizations, permits and supplements or amendments thereto required by any Applicable Laws and/or for
the ownership of their respective properties or the conduct of their respective businesses, including without limitation as it
relates to a Company Product and as described in the SEC Documents (collectively, “Authorizations”) and such
Authorizations are valid and in full force and effect and the Company is not in violation of any term of any such Authorizations;
(iii) neither the Company nor any of its Subsidiaries has received any written notice of adverse finding or warning letter
from any governmental entity alleging or asserting noncompliance with any Applicable Laws or Authorizations relating to a Company
Product; (iv) neither the Company nor any of its Subsidiaries has received written notice of any ongoing claim, action, suit,
proceeding, hearing, enforcement, investigation, arbitration or other action from any governmental entity or third party alleging
that any Company Product, operation or activity related to a Company Product is in violation of any Applicable Laws or Authorizations
or has any knowledge that any such governmental entity or third party is considering any such claim, litigation, arbitration, action,
suit, investigation or proceeding; (v) neither the Company nor any of its Subsidiaries has received written notice that any
governmental entity has taken, is taking or intends to take action to limit, suspend, modify or revoke any Authorizations or has
any knowledge that any such governmental entity has threatened or is considering such action with respect to a Company Product;
and (vi) the Company and each of its Subsidiaries have filed, obtained, maintained or submitted all reports, documents, forms,
notices, applications, records, claims, submissions and supplements or amendments as required by any Applicable Laws or Authorizations
and that all such reports, documents, forms, notices, applications, records, claims, submissions and supplements or amendments
were complete, correct and not misleading on the date filed (or were corrected or supplemented by a subsequent submission). To
the Company’s knowledge, neither the Company nor any of its Subsidiaries, directors, officers, employees or agents, has made,
or caused the making of, any false statements on, or material omissions from, any other records or documentation prepared or maintained
to comply with the requirements of any governmental entity.


 


4.20      Taxes;
Section 1202 Stock. 


 


(a)          The
Company and each of its Subsidiaries has filed all material tax returns that are required to be filed or has requested valid extensions
thereof. All such tax returns are correct and complete in all material respects for the periods to which such tax returns relate,
and the Company and each of its Subsidiaries has paid all taxes required to be paid by them and any other assessment, fine or penalty
levied against it, to the extent that any of the foregoing is due and payable, except for any such assessment, fine or penalty
that is currently being contested in good faith or as would not have or reasonably be expected to have, individually or in the
aggregate, a Material Adverse Effect, whether or not arising from transactions in the ordinary course of business.  There
are in effect no waivers of applicable statutes of limitations with respect to taxes for any year.


 




    	 



     


    

 


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(b)          As
of and immediately following the Closing: (i) the Company will meet all of the active business requirements described in Section
1202 of the Internal Revenue Code; (ii) the Company will not have made any purchases of its own stock described in Section 1202(c)(3)(B)
of the Internal Revenue Code  during the one-year period preceding the Closing, except for purchases that are disregarded
for such purposes under Treasury Regulations Section 1.1202-2; and (iii) the Company's aggregate gross assets, as defined by Section
1202(d)(1) of the Internal Revenue Code, at no time between incorporation and through the Closing have exceeded $50 million, taking
into account the assets of any corporation required to be aggregated with the Company in accordance with Section 1202(d)(1) of
the Internal Revenue Code.


 


4.21      Transfer
Taxes.  There are no transfer taxes or other similar fees or charges under Federal law or the laws of any state, or
any political subdivision thereof, required to be paid in connection with the execution and delivery of this Agreement or the issuance
by the Company or sale by the Company of the Shares.


 


4.22      Investment
Company.  The Company is not and, after giving effect to the offering and sale of the Shares, will not be an “investment
company” as defined in the Investment Company Act of 1940, as amended.


 


4.23      Insurance. 
The Company and each of its Subsidiaries are insured by insurers of recognized financial responsibility against such losses and
risks and in such amounts as are reasonable and customary in the business in which it is engaged; all policies of insurance and
fidelity or surety bonds insuring the Company and each of its Subsidiaries or their respective businesses, assets, employees, officers
and directors are in full force and effect; the Company and each of its Subsidiaries is in compliance with the terms of such policies
and instruments in all material respects; and there are no claims by the Company or any of its Subsidiaries under any such policy
or instrument as to which any insurance company is denying liability or defending under a reservation of rights clause; neither
the Company nor any of its Subsidiaries has been refused any insurance coverage sought or applied for; and the Company has no reason
to believe that it will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar
coverage from similar insurers as may be necessary to continue its business at a cost that would not have or reasonably be expected
to have, individually or in the aggregate, a Material Adverse Effect, whether or not arising from transactions in the ordinary
course of business.


 


4.24      Price
of Common Stock.  The Company has not, and to the Company’s knowledge no one acting on its behalf has, taken,
directly or indirectly, any action designed to cause or result in, or that has constituted or that might reasonably be expected
to constitute the stabilization or manipulation of the price of any securities of the Company to facilitate the sale or resale
of the Shares.


 


4.25      Governmental
Permits, Etc.  The Company and each of its Subsidiaries possess all licenses, certificates, permits and other authorizations
issued by all applicable authorities necessary to conduct their respective businesses, and neither the Company nor any of its Subsidiaries
has received any notice of proceedings relating to the revocation or modification of any such certificate, authorization or permit
which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would have or reasonably be expected
to have a Material Adverse Effect, whether or not arising from transactions in the ordinary course of business.


 


4.26      Internal
Control over Financial Reporting; Sarbanes-Oxley Matters.  The Company maintains a system of internal accounting controls
sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general
or specific authorizations; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity
with generally accepted accounting principles and to maintain asset accountability; (iii) access to assets is permitted only
in accordance with management’s general or specific authorization; and (iv) the recorded accountability for assets is
compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences. The
Company’s internal controls over financial reporting (as defined in Rule 13a-15(f) under the Exchange Act) are
effective to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements
for external purposes in accordance with generally accepted accounting principles and the Company is not aware of any material
weakness in its internal controls over financial reporting.  The Company maintains “disclosure controls and procedures”
(as such term is defined in Rule 13a-15(e) under the Exchange Act); such disclosure controls and procedures are effective.


 




    	 



     


    

 


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4.27      Foreign
Corrupt Practices.  Neither the Company nor any of its Subsidiaries nor, to the knowledge of the Company, any director,
officer, agent, or employee of the Company, has taken any action, directly or indirectly, that would result in a violation by the
Company or such persons of the Foreign Corrupt Practices Act of 1977, as amended, and the rules and regulations thereunder
(the “FCPA”), including, without limitation, making use of the mails or any means or instrumentality of interstate
commerce corruptly in furtherance of an offer, payment, promise to pay or authorization of the payment of any money, or other property,
gift, promise to give, or authorization of the giving of anything of value to any “foreign official” (as such term
is defined in the FCPA) or any foreign political party or official thereof or any candidate for foreign political office, in contravention
of the FCPA.


 


4.28      Labor. 
No labor problem or dispute with the employees of the Company or any of its Subsidiaries exists or, to the knowledge of the Company,
is threatened, and the Company is not aware of any existing or imminent labor disturbance by the employees of any of its principal
suppliers or contractors, that could have a Material Adverse Effect, whether or not arising from transactions in the ordinary course
of business.


 


4.29      ERISA. 
None of the following events has occurred or exists: (i) a failure to fulfill the obligations, if any, under the minimum funding
standards of Section 302 of the United States Employee Retirement Income Security Act of 1974, as amended (“ERISA”),
and the regulations and published interpretations thereunder with respect to a Plan that is required to be funded, determined without
regard to any waiver of such obligations or extension of any amortization period; (ii) an audit or investigation by the Internal
Revenue Service, the U.S. Department of Labor, the Pension Benefit Guaranty Corporation or any other federal or state governmental
agency or any foreign regulatory agency with respect to the employment or compensation of employees by any of the Company that
could have a Material Adverse Effect; (iii) any breach of any contractual obligation, or any violation of law or applicable
qualification standards, with respect to the employment or compensation of employees by the Company that would reasonably be expected
to have a Material Adverse Effect. None of the following events has occurred or is reasonably likely to occur: (i) a material
increase in the aggregate amount of contributions required to be made to all Plans in the current fiscal year of the Company compared
to the amount of such contributions made in the most recently completed fiscal year of the Company; (ii) a material increase
in the “accumulated post-retirement benefit obligations” (within the meaning of Statement of Financial Accounting Standards
106) of the Company compared to the amount of such obligations in the most recently completed fiscal year of the Company; (iii) any
event or condition giving rise to a liability under Title IV of ERISA that could have a Material Adverse Effect; or (iv) the
filing of a claim by one or more employees or former employees of the Company related to their employment that could have a Material
Adverse Effect. For purposes of this paragraph, the term “Plan” means a plan (within the meaning of Section 3(3) of
ERISA) subject to Title IV of ERISA with respect to which the Company may have any liability.


 


4.30      Environmental
Laws.  The Company and each of its Subsidiaries (i) are in compliance with any and all applicable foreign, federal,
state and local laws and regulations relating to the protection of human health and safety, the environment or hazardous or toxic
substances or wastes, pollutants or contaminants (“Environmental Laws”), (ii) have received and are in
compliance with all permits, licenses or other approvals required of them under applicable Environmental Laws to conduct its business
and (iii) have not received notice of any actual or potential liability under any environmental law, except where such non-compliance
with Environmental Laws, failure to receive required permits, licenses or other approvals, or liability would not, individually
or in the aggregate, have or reasonably be expected to have a Material Adverse Effect, whether or not arising from transactions
in the ordinary course of business. Neither the Company nor any of its Subsidiaries has been named as a “potentially responsible
party” under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, as amended.


 


4.31      Money
Laundering Laws. The operations of the Company and its Subsidiaries are and have been conducted at all times in compliance
with applicable financial recordkeeping and reporting requirements and the money laundering statutes and the rules and regulations
thereunder and any related or similar rules, regulations or guidelines, issued, administered or enforced by any governmental agency
(collectively, the “Money Laundering Laws”) and no action, suit or proceeding by or before any court or governmental
agency, authority or body or any arbitrator involving the Company or any of its Subsidiaries with respect to the Money Laundering
Laws is pending or, to the knowledge of the Company, threatened.


 




    	 



     


    

 


Execution Copy


 


4.32      OFAC.
Neither the Company nor any of its Subsidiaries nor, to the knowledge of the Company, any director, officer, agent or employee
of the Company or any of its Subsidiaries (i) is currently subject to any sanctions administered or imposed by the United
States (including any administered or enforced by the Office of Foreign Assets Control of the U.S. Treasury Department, the U.S.
Department of State, or the Bureau of Industry and Security of the U.S. Department of Commerce), the United Nations Security Council,
the European Union, or the United Kingdom (including sanctions administered or controlled by Her Majesty’s Treasury) (collectively,
“Sanctions” and such persons, “Sanction Persons”) or (ii) will, directly or indirectly,
use the proceeds of this offering, or lend, contribute or otherwise make available such proceeds to any subsidiary, joint venture
partner or other person in any manner that will result in a violation of any economic Sanctions by, or could result in the imposition
of Sanctions against, any person (including any person participating in the offering, whether as underwriter, advisor, investor
or otherwise). Neither the Company nor any of its Subsidiaries nor, to the knowledge of the Company, any director, officer, agent,
or employee of the Company or any of its Subsidiaries, is a person that is, or is 50% or more owned or otherwise controlled by
a person that is: (i) the subject of any Sanctions; or (ii) located, organized or resident in a country or territory
that is, or whose government is, the subject of Sanctions that broadly prohibit dealings with that country or territory (currently,
Cuba, Iran, North Korea, Sudan, and Syria) (collectively, “Sanctioned Countries” and each, a “Sanctioned
Country”). Neither the Company nor any of its Subsidiaries has engaged in any dealings or transactions with or for the
benefit of a Sanctioned Person, or with or in a Sanctioned Country, in the preceding three years, nor does the Company or its Subsidiaries
have any plans to increase their respective dealings or transactions with Sanctioned Persons, or with or in Sanctioned Countries.


 


4.33      Rights
Agreements; Approval of Transaction Documents.  The Company does not have in effect any stockholder rights plan or
similar arrangement relating to accumulations of beneficial ownership of Common Stock or a change in control of the Company. 
The Company’s Board has approved the transactions contemplated by the Transaction Documents, including the issuance of the
Shares to the Purchaser (including, without limitation, for purposes of RCW Section 23B.19.040).


 


4.34      Transactions
With Affiliates and Employees.  Except as set forth in the SEC Documents, to the Company’s knowledge, none of
the executive officers or directors of the Company is presently a party to any transaction with the Company or to a presently contemplated
transaction (other than for services as officers and directors) that would be required to be disclosed pursuant to Item 404
of Regulation S-K promulgated under the Securities Act.


 


4.35      No
“Bad Actor” Disqualification.  The Company has conducted a factual inquiry including the procurement of
relevant questionnaires from each Covered Person (as defined below) or other means to determine whether any Covered Person (as
defined below) is subject to any of the “bad actor” disqualifications described in Rule 506(d)(1)(i) to (viii) under
the Securities Act (“Disqualification Events”). To the Company’s knowledge, after conducting such factual
inquiries, no Covered Person is subject to a Disqualification Event, except for a Disqualification Event covered by Rule 506(d)(2) or
(d)(3) under the Securities Act. The Company has complied, to the extent applicable, with any disclosure obligations under
Rule 506(e) under the Securities Act. “Covered Persons” are those persons specified in Rule 506(d)(1) under
the Securities Act, including the Company; any predecessor or affiliate of the Company; any director, executive officer, other
officer participating in the offering, general partner or managing member of the Company; any beneficial owner of 20% or more of
the Company’s outstanding voting equity securities, calculated on the basis of voting power; any promoter (as defined in
Rule 405 under the Securities Act) connected with the Company in any capacity at the time of the sale of the Shares; and any
person that has been or will be paid (directly or indirectly) remuneration for solicitation of purchasers in connection with the
sale of the Shares (a “Solicitor”), any general partner or managing member of any Solicitor, and any director,
executive officer or other officer participating in the offering of any Solicitor or general partner or managing member of any
Solicitor.


 


4.36      Registration
Eligibility.  To the Company’s knowledge, the Company is eligible to register the resale of the Shares by the
Purchasers using Form S-3 promulgated under the Securities Act.


 


4.37      Shell
Company Status.  The Company is not, and has never been, an issuer identified in Rule 144(i)(1).


 




    	 



     


    

 


Execution Copy


 


SECTION 5.


REPRESENTATIONS, WARRANTIES AND COVENANTS
OF THE PURCHASER


 


5.1        
The Purchaser represents and warrants to and covenants with the Company that:


 


(a)          
The Purchaser is a validly existing company and has all requisite corporate power and authority to enter into and consummate the
transactions contemplated by the Transaction Documents and to carry out its obligations hereunder and thereunder, and to invest
in the Shares pursuant to this Agreement.


 


(b)          
The Purchaser acknowledges that it can bear the economic risk and complete loss of its investment in the Shares and has such knowledge
and experience in financial or business matters that it is capable of evaluating the merits and risks of the investment contemplated
hereby. The Purchaser has had an opportunity to receive, review and understand all information related to the Company requested
by it and to ask questions of and receive answers from the Company regarding the Company, its business and the terms and conditions
of the offering of the Shares, and has conducted and completed its own independent due diligence. The Purchaser acknowledges that
the Company has made available the SEC Documents. Based on the information the Purchaser has deemed appropriate, and without reliance
upon any placement agent, it has independently made its own analysis and decision to enter into the Transaction Documents. 
Neither such inquiries nor any other investigation conducted by or on behalf of the Purchaser or its representatives or counsel
shall modify, amend or affect the Purchaser’s right to rely on the truth, accuracy and completeness of the SEC Documents,
the Company’s representations and warranties contained in the Transaction Documents and the Schedule of Exceptions.


 


(c)          
The Shares to be received by the Purchaser hereunder will be acquired for the Purchaser’s own account, not as nominee or
agent, and not with a view to the resale or distribution of any part thereof in violation of the Securities Act, and the Purchaser
has no present intention of selling, granting any participation in, or otherwise distributing the same in violation of the Securities
Act without prejudice, however, to the Purchaser’s right at all times, subject to the terms and conditions of the Transaction
Documents, to sell or otherwise dispose of all or any part of such Shares in compliance with applicable federal and state securities
laws. The Purchaser understands that the Shares are characterized as “restricted securities” under the U.S. federal
securities laws inasmuch as they are being acquired from the Company in a transaction not involving a public offering and that
under such laws and applicable regulations such securities may be resold without registration under the Securities Act only in
certain limited circumstances. Purchaser will not, directly or indirectly, offer, sell, pledge, transfer or otherwise dispose of
(or solicit any offers to buy, purchase or otherwise acquire or take a pledge of) any of the securities purchased hereunder except
in compliance with the Securities Act, applicable blue sky laws, the rules and regulations promulgated thereunder.


 


(d)          
The Purchaser is an “accredited investor” within the meaning of Rule 501(a) under the Securities Act. 
The Purchaser has determined based on its own independent review and such professional advice as it deems appropriate that its
purchase of the Shares and participation in the transactions contemplated by the Transaction Documents (i) are fully consistent
with its financial needs, objectives and condition, (ii) comply and are fully consistent with all investment policies, guidelines
and other restrictions applicable to the Purchaser, (iii) have been duly authorized and approved by all necessary action,
(iv) do not and will not violate or constitute a default under the Purchaser’s certificate of formation or limited liability
company agreement or under any law, rule, regulation, agreement or other obligation by which the Purchaser is bound and (v) are
a fit, proper and suitable investment for the Purchaser, notwithstanding the substantial risks inherent in investing in or holding
the Shares.


 


(e)          
The execution, delivery and performance by the Purchaser of the Transaction Documents have been duly authorized and each has been
duly executed and when delivered will constitute the valid and legally binding obligation of the Purchaser, enforceable against
the Purchaser in accordance with their respective terms, except (i) as limited by applicable bankruptcy, insolvency, reorganization,
moratorium or similar laws relating to or affecting the enforcement of creditors’ rights generally, (ii) as limited
by equitable principles generally, including any specific performance and (iii) with respect to the Registration Rights Agreement,
as rights to indemnity or contribution may be limited by state or federal laws or public policy underlying such laws.


 




    	 



     


    

 


Execution Copy


 


(f)           
The Purchaser is not a broker or dealer registered pursuant to Section 15 of the Exchange Act (a “registered broker-dealer”)
and is not affiliated with a registered broker dealer.  The Purchaser is not party to any agreement for distribution of any
of the Shares.


 


(g)          
The Purchaser shall have completed and delivered to the Company no later than the Closing Date, the Purchaser Questionnaire for
use in preparation of the Registration Statement (as such term is defined in the Registration Rights Agreement), and the answers
to the Purchaser Questionnaire are true and correct in all material respects as of the date of this Agreement and will be true
and correct as of the Closing Date and the effective date of the Registration Statement; provided that the Purchaser shall be entitled
to update such information by providing notice thereof to the Company before the effective date of such Registration Statement.


 


(h)          
The Purchaser understands that no United States federal or state agency, or similar agency of any other country, has reviewed,
approved, passed upon, or made any recommendation or endorsement of the Company or the purchase of the Shares.


 


(i)           
The Purchaser has no present intent to effect a “change of control” of the Company as such term is understood under
the rules promulgated pursuant to Section 13(d) of the Exchange Act.


 


(j)           
The Purchaser has not taken any of the actions set forth in, and is not subject to, the disqualification provisions of Rule 506(d)(1) of
the Securities Act.


 


(k)          
The Purchaser did not learn of the investment in the Shares as a result of any general solicitation or general advertising.


 


(l)           
The Purchaser’s offices in which its investment decision with respect to the Shares was made are located at the address immediately
below such Purchaser’s name in Section 12 hereof.


 


(m)         
The Purchaser (including any person controlling, controlled by, or under common control with such Purchaser, as the term “control”
is defined pursuant to the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and its implementing regulations (the
“HSR Act”)) in connection with the consummation of the transactions contemplated by this Agreement will not
be required to and will not complete a filing with the U.S. government pursuant to the HSR Act.


 


(n)          
As of immediately prior to the closing of the transactions contemplated hereby, neither the Purchaser nor any of its Affiliates
beneficially owns any shares of Common Stock of the Company to the extent such beneficial ownership would, as a result of the transactions
contemplated hereby, (i) require approval of the Company’s shareholders under NASDAQ Listing Rule 5635(b) of
the transactions contemplated hereby or (ii) result in required disclosure under Section 13 of the Exchange Act by the
Purchaser or any of its Affiliates of beneficial ownership of shares of Common Stock of the Company in excess of the Shares plus
any other shares held by Affiliates of the Company.


 


5.2        
Other than consummating the transactions contemplated hereunder, the Purchaser has not, nor has any person acting on behalf of
or pursuant to any understanding with the Purchaser, directly or indirectly executed any purchases or sales, including all “short
sales” as defined in Rule 200 of Regulation SHO under the Exchange Act (but shall not be deemed to include the location
and/or reservation of borrowable shares of Common Stock) (“Short Sales”), of the securities of the Company during
the period commencing as of March 28, 2018 and ending immediately prior to the Effective Date.  The Purchaser has maintained
the confidentiality of all disclosures made to it in connection with this transaction (including the existence and terms of this
transaction). Notwithstanding the foregoing, for avoidance of doubt, nothing contained herein shall constitute a representation
or warranty, or preclude any actions, with respect to the identification of the availability of, or securing of, available shares
to borrow in order to effect Short Sales or similar transactions in the future.


 


5.3        
The Purchaser understands that nothing in this Agreement or any other materials presented to the Purchaser in connection with the
purchase and sale of the Shares constitutes legal, tax or investment advice.  The Purchaser has consulted such legal, tax
and investment advisors as it, in its sole discretion, has deemed necessary or appropriate in connection with its purchase of the
Shares.


 




    	 



     


    

 


Execution Copy


 


5.4        
Legends.


 


(a)          
The Purchaser understands that, until such time as the Shares or any Additional Shares have been sold pursuant to the Registration
Statement or the Shares or Additional Shares may be sold pursuant to Rule 144 under the Securities Act (“Rule 144”)
without any restriction as to the number of securities as of a particular date that can then be immediately sold, the any certificate
or book entry notations evidencing the Shares or Additional Shares may bear one or more legends in substantially the following
form and substance:


 


“THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER
THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”). THEY MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED
OR HYPOTHECATED IN THE ABSENCE OF A REGISTRATION STATEMENT IN EFFECT WITH RESPECT TO THE SECURITIES UNDER THE SECURITIES ACT OR
AN OPINION OF COUNSEL SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED OR UNLESS SOLD PURSUANT TO RULE 144 OF
THE SECURITIES ACT.”


 


In addition, the stock certificate or any
book entry notations representing the Shares or Additional Shares may contain:


 


(i)           
Any legend required by the blue sky laws of any state to the extent such laws are applicable to the sale of such Shares or Additional
Shares hereunder.


 


(ii)          
A legend regarding affiliate status of the Purchaser set forth in Schedule 1 hereto, in the form included therein.


 


(b)          
The Company agrees that at such time as such legend is no longer required under this Section, it will, following the delivery by
the Purchaser to the Company or the Company’s transfer agent of a certificate representing the Shares, as applicable and
if such Shares are certificated, issued with a restrictive legend, together with such representations and covenants of the Purchaser
or the Purchaser’s executing broker as the Company may reasonably require in connection therewith, promptly deliver or cause
to be delivered to the Purchaser a book entry position representing such Shares that is free from any legend referring to the Securities
Act.  The Company shall not make any notation on its records or give instructions to any transfer agent of the Company that
enlarge the restrictions on transfer set forth in this Section.  Certificates for Shares subject to legend removal hereunder
shall be transmitted by the transfer agent of the Company to the Purchaser by crediting the account of the Purchaser’s prime
broker with the Depository Trust Company (“DTC”).  All costs and expenses related to the removal of the
legends and the reissuance of any Shares shall be borne by the Company; provided, however, that the Purchaser shall be responsible
for the costs of its counsel and advisors.


 


(c)          
The restrictive legend set forth in this section above shall be removed and the Company shall issue a certificate or book entry
position without such restrictive legend or any other restrictive legend to the holder of the applicable shares upon which it is
stamped or issue to such holder by electronic delivery with the applicable balance account at DTC or in physical certificated shares,
if appropriate, if (i) such Shares are registered for resale under the Securities Act (provided that, if the Purchaser is
selling pursuant to the effective registration statement registering the Shares for resale, the Purchaser agrees to only sell such
Shares during such time that such registration statement is effective and the Purchaser is not aware or has not been notified by
the Company that such registration statement has been withdrawn or suspended, and only as permitted by such registration statement);
(ii) such Shares are sold or transferred pursuant to Rule 144 (if the transferor is not an affiliate of the Company);
or (iii) such Shares are eligible for sale without the requirement for the Company to be in compliance with the current public
information required under Rule 144 as to such securities and without volume or manner-of-sale restrictions.  Subject
to receipt of such representations, and covenants as are contemplated hereby, following the earlier of (i) the effective date
of the Registration Statement or (ii) Rule 144 becoming available for the resale of the Shares, without the requirement
for the Company to be in compliance with the current public information required under Rule 144 as to the Shares and without
volume or manner-of-sale restrictions, the Company shall promptly issue to the Company’s transfer agent, if required by the
transfer agent, the instructions with respect to legend removal consistent with this Section and shall cause its counsel to
deliver any legend removal opinion required by the transfer agent.  Any fees associated with the issuance of such opinion
or the removal of such legend shall be borne by the Company; provided, however, that the Purchaser shall be responsible for the
costs of its counsel and advisors.


 




    	 



     


    

 


Execution Copy


 


5.5        
Restricted Securities.  The Purchaser understands that the Shares are characterized as “restricted securities”
under the federal securities laws inasmuch as they are being acquired from the Company in a transaction not involving a public
offering and that under such laws and applicable regulations such Shares may be resold without registration under the Securities
Act only in certain limited circumstances.  In this connection, the Purchaser represents that it is familiar with Rule 144,
as presently in effect, and understands the resale limitations imposed thereby and by the Securities Act.


 


SECTION 6.


CONDITIONS TO COMPANY’S OBLIGATIONS
AT THE CLOSING


 


The Company’s obligation to complete
the sale and issuance of the Shares and deliver Shares to the Purchaser at the Closing shall be subject to the following conditions
to the extent not waived by the Company:


 


6.1        
Receipt of Payment.  The Company shall have received payment, by wire transfer of immediately available funds,
in the full amount of the purchase price for the Shares being purchased by the Purchaser at the Closing.


 


6.2        
Representations and Warranties.  The representations and warranties made by the Purchaser in Section 5
hereof shall be true and correct when made, and shall be true and correct on the Closing Date with the same force and effect as
if they had been made on and as of said date. The Purchaser shall have performed in all material respects all obligations and covenants
herein required to be performed by it on or prior to the Closing Date.


 


6.3        
Receipt of Executed Documents.  The Purchaser shall have executed and delivered to the Company the Registration
Rights Agreement, the Voting Agreement, and the Purchaser Questionnaire.


 


 


SECTION 7.


CONDITIONS TO PURCHASER’S OBLIGATIONS
AT THE CLOSING


 


The Purchaser’s obligation to accept
delivery of the Shares and to pay for the Shares shall be subject to the following conditions to the extent not waived by the Purchaser:


 


7.1        
Representations and Warranties Correct.  The representations and warranties made by the Company in Section 4
hereof shall be true and correct as of, and as if made on, the date of this Agreement and the Closing Date, except to the extent
any such representation or warranty expressly speaks as of an earlier date, in which case such representation or warranty shall
be true and correct as of such earlier date. The Company shall have performed in all material respects all obligations and covenants
herein required to be performed by it on or prior to the Closing Date.


 


7.2        
Receipt of Executed Registration Rights Agreement.  The Company shall have executed and delivered to the Purchaser
the Registration Rights Agreement.


 


7.3        
Receipt of Executed Voting Agreement.  The Company shall have executed and delivered to the Purchaser the Voting
Agreement.


 


7.4        
Certificate.  The Purchaser shall have received a certificate signed by the Chief Executive Officer or the Chief
Financial Officer to the effect that the representations and warranties of the Company in Section 4 hereof are true and correct
in all material respects as of, and as if made on, the date of this Agreement and as of the Closing Date and that the Company has
satisfied in all material respects all of the conditions set forth in this Section 7.


 


7.5        
Good Standing.  The Company is validly existing as a corporation in good standing under the laws of Washington.


 




    	 



     


    

 


Execution Copy


 


7.6        
Judgments.  No judgment, writ, order, injunction, award or decree of or by any court, or judge, justice or magistrate,
including any bankruptcy court or judge, or any order of or by any governmental authority, shall have been issued, and no action
or proceeding shall have been instituted by any governmental authority, enjoining or preventing the consummation of the transactions
contemplated hereby.


 


7.7        
Stop Orders.  No stop order or suspension of trading shall have been imposed by NASDAQ, the SEC or any other
governmental regulatory body with respect to public trading in the Common Stock.


 


SECTION 8.


TERMINATION OF OBLIGATIONS TO EFFECT
CLOSING; EFFECTS


 


8.1        
The obligations of the Company, on the one hand, and the Purchaser, on the other hand, to effect the Closing shall terminate as
follows:


 


(a)           
upon the mutual written consent of the Company and the Purchaser;


 


(b)          
by the Company if any of the conditions set forth in Section 6 shall have become incapable of fulfillment, and shall not have
been waived by the Company; or


 


(c)           
by the Purchaser if any of the conditions set forth in Section 7 shall have become incapable of fulfillment, and shall not
have been waived by the Purchaser.


 


8.2         
Nothing in this Section 8 shall be deemed to release any party from any liability for any breach by such party of the terms
and provisions of this Agreement or the other Transaction Documents or to impair the right of any party to compel specific performance
by any other party of its obligations under this Agreement or the other Transaction Documents.


 


SECTION 9.


NO BROKER’S FEES


 


The Company and the Purchaser hereby represent
that there are no brokers or finders entitled to compensation in connection with the sale of the Shares, and shall indemnify each
other for any such fees for which they are responsible.


 


SECTION 10.


ADDITIONAL AGREEMENTS OF THE PARTIES


 


10.1        NASDAQ Listing. Prior to the Closing, the Company shall file with NASDAQ a Notification Form: Listing of Additional
Shares for the listing of the Shares and the Company shall use commercially reasonable efforts to cause such filing to be approved
by NASDAQ and, in accordance, therewith, will use commercially reasonable efforts to comply in all respects with the Company’s
reporting, filing and other obligations under the bylaws or rules of such market or exchange, as applicable.


 


10.2      
Access to Information. From the date hereof until the Closing, the Company will make reasonably available to the
Purchaser’s representatives, consultants and their respective counsels for inspection, such information and documents as
the Purchaser reasonably requests, and will make available at reasonable times and to a reasonable extent officers and employees
of the Company to discuss the business and affairs of the Company.


 


10.3       Termination of Covenants.  The provisions of Section 10.1-10.2 shall terminate and be of no further force
and effect on the date on which the Company’s obligations under the Registration Rights Agreement to register or maintain
the effectiveness of any registration covering the Registrable Securities (as such term is defined in the Registration Rights Agreement)
shall terminate.


 




    	 



     


    

 


Execution Copy


 


10.4      
Form D; Blue Sky Filings. The Company agrees to timely file a Form D with respect to the Shares and to
provide a copy thereof, promptly upon request of the Purchaser. The Company shall take such action as the Company shall reasonably
determine is necessary in order to obtain an exemption for, or to qualify the Shares for, sale to the Purchaser at the Closing
under applicable securities or “Blue Sky” laws of the states of the United States, and shall provide evidence of such
actions promptly upon request of the Purchaser.


 


10.5      
Integration. The Company shall not, and shall use its commercially reasonable efforts to ensure that no affiliate
of the Company shall, sell, offer for sale or solicit offers to buy or otherwise negotiate in respect of any security (as defined
in Section 2 of the Securities Act) that will be integrated with the offer or sale of the Shares in a manner that would require
the registration under the Securities Act of the sale of the Shares to the Purchaser, or that will be integrated with the offer
or sale of the Shares for purposes of the rules and regulations of any trading market such that it would require stockholder
approval prior to the closing of such other transaction unless stockholder approval is obtained before the closing of such subsequent
transaction.


 


10.6      
Short Sales and Confidentiality After the Date Hereof. The Purchaser covenants that neither it nor any affiliates
acting on its behalf or pursuant to any understanding with it will execute any Short Sales during the period from the date hereof
until the earlier of such time as (i) after the transactions contemplated by this Agreement are first publicly announced or
(ii) this Agreement is terminated in full. The Purchaser covenants that until such time as the transactions contemplated by
this Agreement are publicly disclosed in accordance with Section 10.6, the Purchaser will maintain the confidentiality of
all disclosures made to it in connection with this transaction (including the existence and terms of this transaction). The Purchaser
understands and acknowledges that the SEC currently takes the position that coverage of short sales of shares of the Common Stock
“against the box” prior to effectiveness of a resale registration statement with securities included in such registration
statement would be a violation of Section 5 of the Securities Act, as set forth in Item 239.10 of the Securities Act
Rules Compliance and Disclosure Interpretations compiled by the Office of Chief Counsel, Division of Corporation Finance.


 


10.7       Securities
Laws Disclosure; Publicity.  By 9:00 a.m., New York City time, on the third (3rd) business day immediately following
the date of this Agreement, each of the Company and the Purchaser shall issue a press release, in each case, reasonably acceptable
to the other party, disclosing the transactions contemplated hereby.  On or before the fourth trading day immediately following
the execution of this Agreement, the Company will file a Current Report on Form 8-K (the “8-K”) with the
Commission describing the terms of the Transaction Documents (and including as exhibits to such Current Report on Form 8-K
the agreements required to be filed in connection therewith).  Notwithstanding the foregoing, the Company shall not publicly
disclose the name of the Purchaser, or include the name of the Purchaser in any public filing with the Commission or any regulatory
agency with the exception of NASDAQ, without the prior written consent of the Purchaser, which consent shall not be unreasonably
withheld, conditioned or delayed, except: (a) as required by federal securities law in connection with (i) any registration
statement contemplated by the Registration Rights Agreement and (ii) the filing of final Transaction Documents with the Commission;
(b) the filing of a Form D with the Commission under the Securities Act and (c) to the extent such disclosure is
required by law or NASDAQ regulations (other than the submission of a listing of additional shares form), in which case the Company
shall provide the Purchaser with prior notice of such disclosure permitted under this clause (c). As of the time of the filing
of the 8-K, the Purchaser shall not be in possession of any material, non-public information received from the Company, any subsidiary
of the Company or any of their respective officers, directors, employees or agents, pursuant to the transactions contemplated by
this Agreement that is not disclosed in the 8-K, press release or other disclosure by the Company that complies with the requirements
of Regulation FD.


 


10.8       Additional
Share Purchase Rights. The Company grants to Purchaser the right to purchase additional shares of Common Stock (the “Additional
Shares”) on the terms set forth in Appendix IV.


 




    	 



     


    

 


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SECTION 11.

INDEMNIFICATION


 


11.1      
Indemnification by the Company.  The Company agrees to indemnify and hold harmless the Purchaser and its directors,
officers, shareholders, members, partners, employees and agents, and each Person, if any, who controls any Purchaser (within the
meaning of Section 15 of the Securities Act and Section 20 of the Exchange Act), and the directors, officers, shareholders,
agents, members, partners, employees or agents of such controlling Person (each, a “Purchaser Indemnified Party”),
against any losses, claims, damages, liabilities or expenses, joint or several, to which such Purchaser Indemnified Party may become
subject under the Securities Act, the Exchange Act, or any other federal or state statutory law or regulation, or at common law
(including in settlement of any litigation, if such settlement is effected with the written consent of the Company), insofar as
such losses, claims, damages, liabilities or expenses (or actions in respect thereof as contemplated below) arise out of or are
based in whole or in part on (i) any inaccuracy in the representations and warranties of the Company contained in this Agreement
or (ii) any failure of the Company to perform its obligations hereunder, and will reimburse each Purchaser Indemnified Party
for legal and other expenses reasonably incurred as such expenses are reasonably incurred by such Purchaser Indemnified Party in
connection with investigating, defending, settling, compromising or paying such loss, claim, damage, liability, expense or action;
provided, however, that the Company will not be liable in any such case to the extent that any such loss, claim, damage, liability
or expense arises out of or is based upon (1) the failure of such Purchaser Indemnified Party to comply with the covenants
and agreements contained in Section 5, Section 6 and Section 10.6 above respecting sale of the Shares, or (2) the
inaccuracy of any representations made by such Purchaser Indemnified Party herein.


 


11.2      
Indemnification by the Purchaser.  The Purchaser shall indemnify and hold harmless the Company and its directors,
officers, shareholders, members, partners, employees and agents, and each Person, if any, who controls the Company (within the
meaning of Section 15 of the Securities Act and Section 20 of the Exchange Act), and the directors, officers, shareholders,
agents, members, partners, employees or agents of such controlling Person (each, a “Company Indemnified Party”)
against any losses, claims, damages, liabilities or expenses to which such Company Indemnified Party may become subject, under
the Securities Act, the Exchange Act, or any other federal or state statutory law or regulation, or at common law or otherwise
(including in settlement of any litigation, if such settlement is effected with the written consent of the Purchaser) insofar as
such losses, claims, damages, liabilities or expenses (or actions in respect thereof as contemplated below) arise out of or are
based upon (i) any failure by the Purchaser to comply with the covenants and agreements contained in Section 5, Section 6
and Section 10.6 above or (ii) the inaccuracy of any representation made by the Purchaser herein, and will reimburse
such Company Indemnified Party for any legal and other expense reasonably incurred, as such expenses are reasonably incurred by
such Company Indemnified Party in connection with investigating, defending, settling, compromising or paying any such loss, claim,
damage, liability, expense or action.


 


SECTION 12.


NOTICES


 


All notices, requests, consents and other
communications hereunder shall be in writing, shall be sent by confirmed facsimile or electronic mail, or mailed by first-class
registered or certified airmail, or nationally recognized overnight express courier, postage prepaid, and shall be deemed given
when so sent in the case of facsimile or electronic mail transmission, or when so received in the case of mail or courier, and
addressed as follows:


 


	if to the Company, to:	ClearSign Combustion Corporation
	 	12870 Interurban Avenue South
	 	Seattle, WA 98168
	 	Attention:  Chief Executive Officer
	 	E-Mail:  Steve.Pirnat@clearsign.com
	 	Facsimile:  206.673.4848


 


	with a copy (which shall not constitute notice) to:	Mitchell Silberberg & Knupp LLP
	 	12 East 49th Street, 30th Floor
	 	New York, NY 10017
	 	Attn.:  Melanie Figueroa, Esq.
	 	E-Mail:  mxf@msk.com
	 	Facsimile:  212.509.7239


 




    	 



     


    

 


Execution Copy


 


	if to the Purchaser, to:	CLIRSPV LLC
	 	119 Warren Ave 
	 	3rd Floor 
	 	Spring Lake, NJ 07762 
	 	Attention: Robert T. Hoffman Sr.
	 	E-Mail:  rhoffman@princetonopp.com


 


	with copies (which shall not constitute notice) to:	Bressler, Amery & Ross
	 	325 Columbia Turnpike
	 	Florham Park, NJ 07932 
	 	Attention:  Kim Larsen
	 	E-Mail: Klarsen@bressler.com


 


    ,
or to such other person, at such other place or in such manner as one party shall designate to other party in writing.


 


SECTION 13.


MISCELLANEOUS


 


13.1      
Payment of Fees and Expenses.  Each of the Company and the Purchaser shall bear its own expenses and legal fees
incurred on its behalf with respect to this Agreement and the transactions contemplated hereby, provided, however, that the Company
shall pay Purchaser at Closing $75,000 on a non-accountable basis for its expenses incurred in connection with this Agreement.
Should the Company refuse to enter into the Transaction Documents or to close the sale of the Shares pursuant to the Transaction
Documents, in each case through no fault of the Purchaser, the Company shall pay Princeton Opportunity Management LLC a break-up
fee of $75,000.   If any action at law or in equity is necessary to enforce or interpret the terms of this Agreement, the
prevailing party shall be entitled to reasonable attorney’s fees, costs and necessary disbursements in addition to any other
relief to which such party may be entitled.


 


13.2      
Waivers and Amendments.  Neither this Agreement nor any provision hereof may be changed, waived, discharged,
terminated, modified or amended except upon the written consent of the Company and the Purchaser.


 


13.3      
Replacement of Shares.  If the Shares are certificated and any certificate or instrument evidencing any Shares
is mutilated, lost, stolen or destroyed, the Company shall issue or cause to be issued in exchange and substitution for and upon
cancellation thereof, or in lieu of and substitution therefor, a new certificate or instrument, but only upon receipt of evidence
reasonably satisfactory to the Company and the Company’s transfer agent of such loss, theft or destruction and the execution
by the holder thereof of a customary lost certificate affidavit of that fact and an agreement to indemnify and hold harmless the
Company and the Company’s transfer agent for any losses in connection therewith or, if required by the transfer agent, a
bond in such form and amount as is required by the transfer agent.  The applicants for a new certificate or instrument under
such circumstances shall also pay any reasonable third-party costs associated with the issuance of such replacement Shares. 
If a replacement certificate or instrument evidencing any Shares is requested due to a mutilation thereof, the Company may require
delivery of such mutilated certificate or instrument as a condition precedent to any issuance of a replacement.


 


13.4      
Governing Law; Submission to Jurisdiction.  All questions concerning the construction, validity, enforcement
and interpretation of the Transaction Documents shall be governed by and construed and enforced in accordance with the internal
laws of the State of New York, without regard to the principles of conflicts of law thereof.  Each party agrees that all legal
proceedings concerning the interpretations, enforcement and defense of the transactions contemplated by this Agreement and any
other Transaction Documents (whether brought against a party hereto or its respective affiliates, directors, officers, shareholders,
employees or agents) shall be commenced exclusively in the state and federal courts sitting in the County of New York, in the State
of New York. Each party hereby irrevocably submits to the exclusive jurisdiction of the state and federal courts sitting in the
County of New York, in the State of New York, for the adjudication of any dispute hereunder or in connection herewith or with any
transaction contemplated hereby or discussed herein (including with respect to the enforcement of any of the Transaction Documents),
and hereby irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally
subject to the jurisdiction of any such court, that such suit, action or proceeding is improper or is an inconvenient venue for
such proceeding.  Each party hereby irrevocably waives personal service of process and consents to process being served in
any such suit, action or proceeding by mailing a copy thereof via registered or certified mail or overnight delivery (with evidence
of delivery) to such party at the address in effect for notices to it under this Agreement and agrees that such service shall constitute
good and sufficient service of process and notice thereof.  Nothing contained herein shall be deemed to limit in any way any
right to serve process in any other manner permitted by law.


 




    	 



     


    

 


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13.5      
Successors and Assigns.  Except as otherwise expressly provided herein, the provisions hereof shall inure to
the benefit of, and be binding upon, the successors, assigns, heirs, executors and administrators of the parties hereto. This Agreement,
or any rights or obligations hereunder, may not be assigned by either party without the prior written consent of the other.


 


13.6      
Headings.  The headings of the various sections of this Agreement have been inserted for convenience of reference
only and shall not be deemed to be part of this Agreement.


 


13.7      
Severability.  In case any provision contained in this Agreement should be invalid, illegal or unenforceable
in any respect, the validity, legality and enforceability of the remaining provisions contained herein shall not in any way be
affected or impaired thereby.


 


13.8      
Counterparts.  This Agreement may be executed in counterparts, each of which shall be deemed an original but
which together shall constitute one and the same instrument.


 


13.9      
Entire Agreement.  This Agreement and other documents delivered pursuant hereto, including the exhibits and
the Schedule of Exceptions, constitute the full and entire understanding and agreement between the parties with regard to the subjects
hereof and thereof.


  


13.10    
Survival.  The representations, warranties, covenants and agreements made in this Agreement shall survive any
investigation made by the Company or the Purchaser and the Closing.


 


[Signature pages follow.]


 




    	 



     


    

 


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IN WITNESS WHEREOF, the parties hereto
have caused this Agreement to be executed by their duly authorized representatives as of the day and year first above written.


 


	 	COMPANY:
	 	 
	 	CLEARSIGN COMBUSTION CORPORATION
	 	 
	 	By:	/s/ Stephen E. Pirnat
	 	Name:	Stephen E. Pirnat
	 	Title:	Chief Executive Officer
	 	 
	 	PURCHASER:
	 	 
	 	CLIRSPV LLC
	 	 
	 	
	 	 
	 	By:	/s/ Robert
T. Hoffman Sr.
	 	Name:	Robert T. Hoffman Sr.
	 	Title:	Managing Member


 




    	 



     


    

 


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APPENDIX I


 


PURCHASER QUESTIONNAIRE


 


To: ClearSign Combustion Corporation


 


This Purchaser Questionnaire (“Questionnaire”)
must be completed by each potential investor in connection with the offer and sale of the shares of the common stock, par value
$0.0001 per share (the “Securities”), of ClearSign Combustion Corporation, a Washington corporation (the “Corporation”). 
The Securities are being offered and sold by the Corporation without registration under the Securities Act of 1933, as amended
(the “Securities Act”), and the securities laws of certain states, in reliance on the exemptions contained in
Section 4(a)(2) of the Securities Act and on Regulation D promulgated thereunder and in reliance on similar exemptions
under applicable state laws.  The Corporation must determine that a potential investor meets certain suitability requirements
before offering or selling the Securities to such investor.  The purpose of this Questionnaire is to assure the Corporation
that each investor will meet the applicable suitability requirements.  The information supplied by you will be used in determining
whether you meet such criteria, and reliance upon the private offering exemptions from registration is based in part on the information
herein supplied.


 


This Questionnaire does not constitute an offer to sell or a
solicitation of an offer to buy any security.  By signing this Questionnaire, you will be authorizing the Corporation to provide
a completed copy of this Questionnaire to such parties as the Corporation deems appropriate in order to ensure that the offer and
sale of the Securities will not result in a violation of the Securities Act or the securities laws of any state and that you otherwise
satisfy the suitability standards applicable to purchasers of the Securities.  All potential investors must answer all applicable
questions and complete, date and sign this Questionnaire.  Please print or type your responses and attach additional sheets
of paper if necessary to complete your answers to any item.


 


PART A. BACKGROUND INFORMATION


 


Name of Beneficial Owner of the Securities:  clirSPV LLC


 


Business Address:  119 Warren Avenue, 3rd Floor


 


	City: Spring Lake	State: NJ	Zip Code: 07762


 


Telephone Number: 732 282 0743


 


If a corporation, partnership, limited liability company,
trust or other entity:


 


Type of entity: LLC


 


	State of formation:  Delaware	Approximate Date of formation: Feb 16 2018


 


Were you formed for the purpose of
investing in the securities being offered?     Yes  x               No 
 ̈


 


If an individual:


	Residence Address:	 
	 	(Number and Street)


 


	City:                  	State:                 	Zip Code:        
	 	 	 
	Telephone Number:             	 	 
	 	 	 
	Age:                   	Citizenship:             	Where registered to vote:                


 




    	 



     


    

 


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Set forth in the space provided below the state(s), if any,
in the United States in which you maintained your residence during the past two years and the dates during which you resided in
each state:


 


Are you a director or executive officer
of the Corporation?       Yes   ̈                 No 
 ̈


 


Social Security or Taxpayer Identification No.:     82-5195800       


 


PART B. ACCREDITED INVESTOR QUESTIONNAIRE


 


In order for the Corporation to offer and
sell the Securities in conformance with state and federal securities laws, the following information must be obtained regarding
your investor status. Please initial each category applicable to you as a purchaser of Securities of the Corporation.


 


	 	 ̈  (1)	A bank as defined in Section 3(a)(2) of the Securities Act, or any savings and loan association or other institution as defined in Section 3(a)(5)(A) of the Securities Act whether acting in its individual or fiduciary capacity;
	 	 	 
	 	 ̈  (2)	A broker or dealer registered pursuant to Section 15 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”);
	 	 	 
	 	 ̈  (3)	An insurance company as defined in Section 2(a)(13) of the Securities Act;
	 	 	 
	 	 ̈  (4)	An investment company registered under the Investment Company Act of 1940 or a business development company as defined in Section 2(a)(48) of that act;
	 	 	 
	 	 ̈  (5)	A Small Business Investment Company licensed by the U.S. Small Business Administration under Section 301(c) or (d) of the Small Business Investment Act of 1958;
	 	 	 
	 	 ̈  (6)	A plan established and maintained by a state, its political subdivisions, or any agency or instrumentality of a state or its political subdivisions, for the benefit of its employees, if such plan has total assets in excess of $5,000,000;
	 	 	 
	 	 ̈  (7)	An employee benefit plan within the meaning of the Employee Retirement Income Security Act of 1974, if the investment decision is made by a plan fiduciary, as defined in Section 3(21) of such act, which is either a bank, savings and loan association, insurance company or registered investment adviser, or if the employee benefit plan has total assets in excess of $5,000,000 or, if a self-directed plan, with investment decisions made solely by persons that are accredited investors;
	 	 	 
	 	 ̈  (8)	A private business development company as defined in Section 202(a)(22) of the Investment Advisers Act of 1940;
	 	 	 
	 	 ̈  (9)	An organization described in Section 501(c)(3) of the Internal Revenue Code, a corporation, Massachusetts or similar business trust, or partnership, not formed for the specific purpose of acquiring the Securities, with total assets in excess of $5,000,000;
	 	 	 
	 	 ̈  (10)	A trust, with total assets in excess of $5,000,000, not formed for the specific purpose of acquiring the Securities, whose purchase is directed by a sophisticated person who has such knowledge and experience in financial and business matters that such person is capable of evaluating the merits and risks of investing in the Corporation;


 




    	 



     


    

 


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	 	 ̈  (11)	A natural person whose individual net worth, or joint net worth with that person’s spouse, at the time of his purchase exceeds $1,000,000 (exclusive of the value of that person’s primary residence);
	 	 	 
	 	 ̈  (12)	A natural person who had an individual income in excess of $200,000 in each of the two most recent years, or joint income with that person’s spouse in excess of $300,000, in each of those years, and has a reasonable expectation of reaching the same income level in the current year;
	 	 	 
	 	 ̈  (13)	An executive officer or director of the Corporation;
	 	 	 
	 	x  (14)	An entity in which all of the equity owners qualify under any of the above subparagraphs.


 


PART C. BAD ACTOR QUESTIONNAIRE


 


		1.	During the past ten years, have you been convicted of
any felony or misdemeanor that is related to any securities matter?



 


Yes    ̈          (If
yes, please continue to Question 1.a)


 


No    x          (If
no, please continue to Question 2)


 


a)          
If your answer to Question 1 was “yes”, was the conviction related to: (i) the purchase or sale of any security;
(ii) the making of any false filing with the Securities and Exchange Commission (the “SEC”); or
(iii) the conduct of an underwriter, broker, dealer, municipal securities dealer, investment adviser or paid solicitor of
purchasers of securities?


 


Yes   ̈          No 
 ̈


 


		2.	Are you subject to any court injunction or restraining
order entered during the past five years that is related to any securities matter?



 


Yes    ̈          (If
yes, please continue to Question 2.a)


 


No    x          (If
no, please continue to Question 3)


 


a)           
If your answer to Question 2 was “yes”, does the court injunction or restraining order currently restrain or enjoin
you from engaging or continuing to engage in any conduct or practice related to: (i) the purchase or sale of any security;
(ii) the making of any false filing with the SEC; or (iii) the conduct of an underwriter, broker, dealer, municipal
securities dealer, investment adviser or paid solicitor of purchasers of securities?


 


Yes   ̈          No 
 ̈


 


		3.	Are you subject to any final order(1) of any governmental
commission, authority, agency or officer(2) related to any securities, insurance or banking matter?



 


 






(1)  A “final order” is defined under Rule 501(g) as
a written directive or declaratory statement issued by a federal or state agency described in Rule 506(d)(1)(iii) under
applicable statutory authority that provides for notice and an opportunity for a hearing, and that constitutes a final disposition
or action by such federal or state agency.


(2)  You may limit your response to final orders of: (i) state
securities commissions (or state agencies/officers that perform a similar function); (ii) state authorities that supervise
or examine banks, savings associations or credit unions; (iii) state insurance commissions (or state agencies/officers that
perform a similar function); (iv) federal banking agencies; (v) the U.S. Commodity Futures Trading Commission; or (vi) the
U.S. National Credit Union Administration.


 




    	 



     


    

 


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Yes    ̈          (If
yes, please continue to Question 3.a)


 


No    x         (If
no, please continue to Question 4)


 


		a)	If your answer to Question 3 was “yes”:



 


		i)	Does the order currently bar you from: (i) associating
with an entity regulated by such commission, authority, agency or officer; (ii) engaging in the business of securities, insurance
or banking; or (iii) engaging in savings association or credit union activities?



 


Yes   ̈             No 
 ̈


 


		ii)	Was the order (i) entered within the past ten years
and (ii) based on a violation of any law or regulation that prohibits fraudulent, manipulative or deceptive conduct?



 


Yes   ̈             No 
 ̈


 


		4.	Are you subject to any SEC disciplinary order?(3)



 


Yes    ̈          (If
yes, please continue to Question 4.a)


 


No    x          (If
no, please continue to Question 5)


 


		a)	If your answer to Question 4 was “yes”, does
the order currently: (i) suspend or revoke your registration as a broker, dealer, municipal securities dealer or investment
adviser; (ii) place limitations on your activities, functions or operations; or (iii) bar you from being associated
with any particular entity or class of entities or from participating in the offering of any penny stock?



 


		5.	Are you subject to any SEC cease and desist order entered
within the past five years?



 


Yes    ̈          (If
yes, please continue to Question 5.a)


 


No    x          (If
no, please continue to Question 6)


 


		a)	If your answer to Question 5 was “yes”, does
the order currently require you to cease and desist from committing or causing a violation or future violation of (i) any
knowledge-based anti-fraud provision of the U.S. federal securities laws(4) or (ii) Section 5 of the Securities
Act?



 


Yes   ̈          No 
 ̈


 


		6.	Have you been suspended or expelled from membership
in, or suspended or barred from association with a member of, a registered national securities exchange or a registered national
or affiliated securities association?



 


 






(3)  You may limit your response to disciplinary orders
issued pursuant to Sections 15(b) or 15B(c) of the Exchange Act or Section 203(e) or (f) of the Investment
Advisers Act of 1940 (the “Advisers Act”).


(4)  Including (but not limited to) Section 17(a)(1) of
the Securities Act, Section 10(b) of the Exchange Act and Rule 10b-5 thereunder, Section 15(c)(1) of the
Exchange Act, and Section 206(1) of the Advisers Act or any other rule or regulation thereunder.


 




    	 



     


    

 


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Yes    ̈          (If
yes, please describe the basis of any such suspension or expulsion and any related details in the space provided under Question
10 below)(5)


 


No    x          (If
no, please continue to Question 7)


 


		7.	Have you registered a securities offering with the SEC,
made an offering under Regulation A or been named as an underwriter in any registration statement or Regulation A offering statement
filed with the SEC?



 


Yes    ̈          (If
yes, please continue to Question 7.a)


 


No    x          (If
no, please continue to Question 8)


 


		a)	If your answer to Question 7 was “yes”:



 


		i)	During the past five years, was any such registration statement
or Regulation A offering statement the subject of a refusal order, stop order or order suspending the Regulation A exemption?



 


Yes   ̈          No 
 ̈


 


		ii)	Is any such registration statement or Regulation A offering
statement currently the subject of an investigation or proceeding to determine whether a stop order or suspension order should
be issued?



 


Yes   ̈          No 
 ̈


 


		8.	Are you subject to a U.S. Postal Service false representation
order entered within the past five years?



 


Yes   ̈          No 
x


 


		9.	Are you currently subject to a temporary restraining
order or preliminary injunction with respect to conduct alleged by the U.S. Postal Service to constitute a scheme or device for
obtaining money or property through the mail by means of false representations?



 


Yes   ̈          No 
x


 


		10.	In the space provided below, describe any facts or circumstances
that caused you to answer “yes” to any Question (indicating the corresponding Question number).   Attach
additional pages if necessary.



 


 






(5)  In providing additional information, please explain
whether or not the suspension or expulsion resulted from “any act or omission to act constituting conduct inconsistent with
just and equitable principles of trade.”


 




    	 



     


    

 


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	A.	FOR EXECUTION BY AN INDIVIDUAL:	 	 
	 	 	 	 
	 	 	 	By:	 
	 	 	 	 
	 	 	 	Print Name:	 
	 	 	 	 
	 	Date	 	 
	 	 	 	 
	B.	FOR EXECUTION BY AN ENTITY:	 	 
	 	 	 	 
	 	 	 	Entity Name:  clirSPV LLC
	 	 	 	 
	 	 	 	
	 	 	 	 
	 	 	 	By:	/s/ Robert
T. Hoffman Sr.
	 	 	 	 
	 	 	 	Print Name:	Robert
T. Hoffman Sr.
	 	 	 	 
	 	 	 	Title:	Managing Member
	 	 	 	 
	 	July
12, 2018	 	 
	 	Date	 	 
	 	 	 	 
	C.	ADDITIONAL SIGNATURES (if required by partnership, corporation or trust document):
	 	 	 	 
	 	 	 	Entity Name:	 
	 	 	 	 
	 	 	 	By:	 
	 	 	 	 
	 	 	 	Print Name:	 
	 	 	 	 
	 	 	 	Title:	 
	 	 	 	 
	 	 	 	 
	 	Date	 	 
	 	 	 	 
	 	 	 	Entity Name:	 
	 	 	 	 
	 	 	 	By:	 
	 	 	 	 
	 	 	 	Print Name:	 
	 	 	 	 
	 	 	 	Title:	 
	 	 	 	 
	 	 	 	 
	 	Date	 	 







 




    	 



     


    

 





Execution Copy


 


APPENDIX II


 


VOTING AGREEMENT


 


This Voting Agreement (this “Agreement”)
is dated as of July __, 2018, by and between ClearSign Combustion Corporation, a Washington corporation (the “Company”)
and CLIRSPV, LLC, a Delaware limited liability Company (“Investor”).


 


RECITALS


 


A.       The
Stock Purchase Agreement, dated as of July __, 2018, by and between the Company and the Investor (the “Purchase Agreement”),
provides for the issuance and sale by the Company to the Investor, and the purchase by the Investor, of shares (collectively, the
“Purchased Shares”) of the Company’s common stock, par value $0.0001 per share (the “Common Stock”);
and


 


B.       As
a condition to consummating the transactions contemplated by the Purchase Agreement, the Investor and the Company have agreed upon
certain rights and obligations as set forth herein, and it is a condition to the closing under the Purchase Agreement that this
Agreement be executed and delivered by the Investor and the Company.


 


AGREEMENT


 


NOW, THEREFORE, IN CONSIDERATION of the
mutual covenants contained in this Agreement, and for other good and valuable consideration, the receipt and sufficiency of which
are hereby acknowledged, the Company and the Investor agree as follows:


 


SECTION 1.


DEFINITIONS


 


As used in this Agreement, the following terms shall have the
following meanings:


 


 


“Affiliate” shall mean,
with respect to any Person, any other Person directly or indirectly Controlling, Controlled by, or under common Control with such
Person; provided, however, that the Company, any of its subsidiaries or any of the Company’s other Controlled Affiliates,
in each case, will not be deemed Affiliates of the Investor for purposes of this Agreement.


 


“Agreement” shall have
the meaning set forth in the Preamble to this Agreement.


 


“beneficial owner,” “beneficially
owns,” “beneficial ownership” and terms of similar import used in this Agreement shall, with respect
to a Person, have the meaning set forth in Rule 13d-3 under the Exchange Act (a) assuming the full conversion into, and exercise
and exchange for, shares of Common Stock of all Common Stock Equivalents beneficially owned by such Person and (b) determined without
regard for the number of days in which such Person has the right to acquire such beneficial ownership.


 


“Board of Directors”
shall mean the Board of Directors of the Company.


  


“Change in Control” shall
mean, with respect to the Company, any of the following events: (a) any Person or Group is or becomes the beneficial owner, directly
or indirectly, of a majority of the total voting power represented by all Shares of Then Outstanding Common Stock; (b) the Company
consolidates with or merges into another corporation or entity, or any corporation or entity consolidates with or merges into the
Company, other than (i) a merger or consolidation which would result in the voting securities of the Company outstanding immediately
prior to such merger or consolidation continuing to represent (either by remaining outstanding or by being converted into voting
securities of the surviving entity or any parent thereof) a majority of the combined voting power of the voting securities of the
Company or such surviving entity or any parent thereof outstanding immediately after such merger or consolidation, or (ii) a merger
or consolidation effected to implement a recapitalization of the Company (or similar transaction) in which no Person becomes the
beneficial owner, directly or indirectly, of a majority of the total voting power of all Shares of Then Outstanding Common Stock;
(c) the Company conveys, transfers or leases all or substantially all of its assets to any Person other than a wholly owned Affiliate
of the Company or (d) individuals who constitute Continuing Directors cease for any reason to constitute at least a majority of
the Board of Directors.


 




    	 



     


    

 


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“Closing Date” shall have the meaning
set forth in the Purchase Agreement.


 


“Common Stock” shall have the meaning
set forth in the Preamble to this Agreement.


 


“Common Stock Equivalents”
shall mean any options, warrants or other securities or rights convertible into or exercisable or exchangeable for, whether directly
or following conversion into or exercise or exchange for other options, warrants or other securities or rights, shares of Common
Stock.


 


“Company” shall have the meaning
set forth in the Preamble to this Agreement.


  


“Continuing Directors”
shall mean the directors of the Company on the date hereof, and each other director, if in each case, such other director’s
nomination for election to the Board of Directors was recommended by, or whose appointment to the Board of Directors was approved
by, at least a majority of the other Continuing Directors.


 


“Control” (including
the correlative terms “Controlled by,” “Controlling,” and “under common Control
with”), as applied to any Person, shall mean the possession, directly or indirectly, of the power to direct or cause
the direction of the management and policies of that Person, whether through the ownership or voting of securities, by contract
or otherwise.


 


“Controlled Affiliate”
shall mean, with respect to a Person, an Affiliate of such Person Controlled by such Person.


   


“Exchange Act” shall
mean the Securities Exchange Act of 1934, as amended, and the rules and regulations of the SEC promulgated thereunder.


 


“Governmental Authority”
shall mean any court, agency, authority, department, regulatory body or other instrumentality of any government or country or of
any national, federal, state, provincial, regional, county, city or other political subdivision of any such government or country
or any supranational organization of which any such country is a member.


 


“Group” shall mean two
or more Persons acting as a partnership, limited partnership, syndicate or other group within the meaning of Section 13(d) of the
Exchange Act.


 


“Initial Designee” shall have the
meaning set forth in Section 2.


 


“Investor” shall have the meaning
set forth in the Preamble to this Agreement.


 


“Investor Designee” shall have
the meaning set forth in Section 2.


 


“Law” or “Laws”
shall mean all laws, statutes, rules, regulations, orders, judgments, injunctions and/or ordinances of any Governmental Authority.


 


“Modified Clause” shall have the
meaning set forth in Section 5.8.


  


“Non-Controlled Affiliate”
shall mean, with respect to a Person, an Affiliate of such Person that is not a Controlled Affiliate of such Person.


   


“Person” shall mean any
individual, partnership, firm, corporation, association, trust, unincorporated organization, government or any department or agency
thereof or other entity.


 




    	 



     


    

 


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“Purchase Agreement”
shall have the meaning set forth in the Preamble to this Agreement, and shall include all appendices, exhibits and schedules attached
thereto.


 


“Purchased Shares” shall
have the meaning set forth in the Preamble to this Agreement, and shall be adjusted for (a) any stock split, stock dividend, share
exchange, merger, consolidation or similar recapitalization and (b) any Common Stock issued as (or issuable upon the exercise of
any warrant, right or other security that is issued as) a dividend or other distribution with respect to, or in exchange or in
replacement of, the Purchased Shares.


 


“Qualified Investor Designee” shall
have the meaning set forth in Section 2.


  


“Registration Rights Agreement”
shall mean the Registration Rights Agreement by and between the Company and the Investor of even date herewith.


 


“Replacement Designee” shall have
the meaning set forth in Section 2.


 


“SEC” shall mean the United States
Securities and Exchange Commission.


 


“Shares of Then Outstanding Common
Stock” shall mean, at any time, the issued and outstanding shares of Common Stock at such time.


 


“Third Party” shall mean
any Person other than the Investor, the Company or any of their respective Affiliates.


 


SECTION 2.


ADDITIONAL AGREEMENTS


 


Board Nomination Right. 
For so long as the Investor beneficially owns at least three million (3,000,000) shares of Common Stock (as adjusted for any stock
split, stock dividend or any subdivision of the Common Stock, or any other reclassification or other similar recapitalization
after the date hereof), or such lesser number of shares of Common Stock which then constitute at least 10% of the Shares of Then
Outstanding Common Stock, at each annual meeting of the stockholders of the Company or at any meeting of the stockholders of the
Company at which members of the Board of Directors are to be elected, or whenever such action is to be taken by written consent
for such purposes, the Company agrees to nominate for election one individual designated by the Investor (an “Investor
Designee”) who shall be reasonably acceptable to the nominating and corporate governance committee of the Board of Directors
(an Investor Designee who satisfied such requirements, a “Qualified Investor Designee”).  The Investor’s
initial designee under this Agreement shall be Robert T. Hoffman Sr. (the “Initial Designee”), whom the Company
agrees is a Qualified Investor Designee.  On or prior to the Closing Date, the Company shall take all actions necessary (including,
if necessary, by approving an enlargement of its Board of Directors to create a vacancy thereon) to cause the appointment to the
Board of Directors of the Initial Designee effective as of the Closing Date, and thereafter, for so long as the Investor’s
board nomination right under this Section 2 continues, the Company will use its commercially reasonable efforts to cause
the election and reelection of such individual to the Board of Directors for so long as he or she is a Qualified Investor Designee
(including recommending that the Company’s stockholders vote in favor of the election of such an individual and otherwise
supporting him for election in a manner no less rigorous and favorable than the manner in which the Company supports its other
nominees), provided that if the Investor determines to designate a different individual (“Replacement Designee”)
as its Investor Designee, and such Replacement Designee is a Qualified Investor Designee, such obligation shall instead apply
to the Replacement Designee.  If any Investor Designee vacates the Board of Directors, the Company shall take all actions
necessary to cause the appointment to the Board of Directors of a Qualified Investor Designee nominated by the Investor to fill
the vacancy and thereafter the Company will use its commercially reasonable efforts to cause the election of such an individual
to the Board of Directors, subject to the same conditions and limitations as set forth in the foregoing sentence.  For avoidance
of doubt, the Investor shall be limited to only one designee serving on the Board at any time pursuant to this Section 2. 
Such designee shall be entitled to the same level of directors’ and officers’ indemnity insurance coverage and indemnity
and exculpation protection (including under any indemnification agreement) as the other members of the Board of Directors. 
For so long as an Investor Designee serves on the Board of Directors, the Company shall maintain in place directors’ and
officers’ indemnity insurance coverage in an amount deemed appropriate by the Board of Directors.  Any Investor Designee
shall be subject to the same Company policies and procedures as the other directors on the Board of Directors, including
with respect to conflicts of interest and recusal from deliberations and voting.


 




    	 



     


    

 


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SECTION 3.


TERMINATION OR SURVIVAL OF CERTAIN RIGHTS
AND OBLIGATIONS


 


Except as otherwise provided in this Agreement,
this Agreement shall terminate in its entirety upon the earlier to occur of (a) the mutual written agreement of the parties;
(b) the occurrence of a Change in Control; and (c) a decline, whether as a result of the Company’s issuance of additional
shares of Common Stock or as a result of the Investor’s sale of shares of the Company’s Common Stock, in the Investor’s
ownership of the Company’s Common Stock to less than 10% of Shares of Then Outstanding Common Stock.  Notwithstanding
the foregoing, the rights and obligations provided in Section 4, and Section 5 shall survive termination of this Agreement.


 


SECTION 4.


NOTICES


 


All notices, requests, consents and other
communications hereunder shall be in writing, shall be sent by confirmed facsimile or electronic mail, or mailed by first-class
registered or certified airmail, or nationally recognized overnight express courier, postage prepaid, and shall be deemed given
when so sent in the case of facsimile or electronic mail transmission, or when so received in the case of mail or courier, and
addressed as follows:


 


	if to the Company, to:	ClearSign Combustion Corporation
	 	12870 Interurban Avenue South
	 	Seattle, WA 98168
	 	Attention:  Chief Executive Officer
	 	E-Mail:  Steve.Pirnat@clearsign.com
	 	Facsimile:  206.673.4848


 


	with a copy (which shall not constitute notice) to:	Mitchell Silberberg & Knupp LLP
	 	12 East 49th Street, 30th Floor
	 	New York, NY 10017
	 	Attn.:  Melanie Figueroa, Esq.
	 	E-Mail:  mxf@msk.com
	 	Facsimile:  212.509.7239


 


	if to the Investor, to:	GPclirSPV LLC
	 	119 Warren Ave 
	 	3rd Floor 
	 	Spring Lake, NJ 07762 
	 	Attention: Robert T. Hoffman Sr.
	 	E-Mail:  rhoffman@princetonopp.com


 


	with copies (which shall not constitute notice) to:	Bressler, Amery & Ross
	 	325 Columbia Turnpike
	 	Florham Park, NJ 07932 
	 	Attention:  Kim Larsen
	 	E-Mail: Klarsen@bressler.com


 


          , or to such other person, at such other
place or in such manner as one party shall designate to other party in writing.


 




    	 



     


    

 


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SECTION 5.


MISCELLANEOUS


 


5.1       
Waivers and Amendments.  Waiver by a party of a breach hereunder by another party shall not be construed as
a waiver of any subsequent breach of the same or any other provision.  No delay or omission by a party in exercising or availing
itself of any right, power or privilege hereunder shall preclude the later exercise of any such right, power or privilege by such
party.  Neither this Agreement nor any provision hereof may be changed, waived, discharged, terminated, modified or amended
except upon the written consent of the Company and the Investor.


 


5.2       Governing
Law; Submission to Jurisdiction.  This Agreement shall be governed by and construed in accordance with the Laws of
the State of New York, without regard to the conflict of laws principles thereof that would require the application of the Law
of any other jurisdiction.  The parties irrevocably and unconditionally submit to the exclusive jurisdiction of the state
and federal courts sitting in the County of New York, in the State of New York, solely and specifically for the purposes of any
action or proceeding arising out of or in connection with this Agreement.


 


5.3       Remedies. 
The rights, powers and remedies of the parties under this Agreement are cumulative and not exclusive of any other right, power
or remedy which such parties may have under any other agreement or Law.  No single or partial assertion or exercise of any
right, power or remedy of a party hereunder shall preclude any other or further assertion or exercise thereof.


 


5.4        Specific
Performance.  The parties hereby acknowledge and agree that the rights of the parties hereunder are special, unique
and of extraordinary character, and that if any party refuses or otherwise fails to act, or to cause its Affiliates to act, in
accordance with the provisions of this Agreement, such refusal or failure would result in irreparable injury to the Company or
the Investor, as the case may be, the exact amount of which would be difficult to ascertain or estimate and the remedies at law
for which would not be reasonable or adequate compensation.  Accordingly, if any party refuses or otherwise fails to act,
or to cause its Affiliates to act, in accordance with the provisions of this Agreement, then, in addition to any other remedy which
may be available to any damaged party at law or in equity, such damaged party will be entitled to seek specific performance and
injunctive relief, without posting bond or other security, and without the necessity of proving actual or threatened damages, which
remedy such damaged party will be entitled to seek in any court of competent jurisdiction.  Notwithstanding this Section 5.4,
except as otherwise provided herein, if any act or failure to act by a Non-Controlled Affiliate of the Investor contravenes this
Agreement (or would contravene this Agreement to the extent it was binding on such Non-Controlled Affiliate, notwithstanding that
it is not binding on such Non-Controlled Affiliate), upon written notice by the Company, the Investor shall use its best efforts
to take or cause such Non-Controlled Affiliate to take appropriate measures to remedy such inaction to the reasonable satisfaction
of the Company.


 


5.5       
Successors and Assigns.  Except as otherwise expressly provided herein, the provisions hereof shall inure to
the benefit of, and be binding upon, the successors, assigns, heirs, executors and administrators of the parties hereto. 
Except as otherwise expressly provided herein, this Agreement, or any rights or obligations hereunder, may not be assigned by either
party without the prior written consent of the other.


 


5.6       Headings. 
The headings of the various sections of this Agreement have been inserted for convenience of reference only and shall not be deemed
to be part of this Agreement.


 


5.7       Severability. 
If, under applicable Laws, any provision hereof is invalid or unenforceable, or otherwise directly or indirectly affects the validity
of any other material provision(s) of this Agreement in any jurisdiction (“Modified Clause”), then, it
is mutually agreed that this Agreement shall endure and that the Modified Clause shall be enforced in such jurisdiction to the
maximum extent permitted under applicable Laws in such jurisdiction; provided that the parties shall consult and use all reasonable
efforts to agree upon, and hereby consent to, any valid and enforceable modification of this Agreement as may be necessary to avoid
any unjust enrichment of either party and to match the intent of this Agreement as closely as possible, including the economic
benefits and rights contemplated herein.


 




    	 



     


    

 


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5.8       Counterparts. 
This Agreement may be executed in counterparts, each of which shall be deemed an original but which together shall constitute one
and the same instrument.


 


5.9        
Entire Agreement.  This Agreement, the Purchase Agreement and the Registration Rights Agreement contain the
entire agreement among the parties with respect to the subject matter hereof and thereof and supersede all prior and contemporaneous
arrangements or understandings, whether written or oral, with respect hereto and thereto.


 


5.10       Third
Party Beneficiaries.  None of the provisions of this Agreement shall be for the benefit of or enforceable by any Third
Party.  No Third Party shall obtain any right under any provision of this Agreement or shall by reason of any such provision
make any claim in respect of any debt, liability or obligation (or otherwise) against any party hereto.


 


5.11       No
Conflicting Agreements.  The Investor hereby represents and warrants to the Company that neither it nor any of its
Affiliates is, as of the date of this Agreement, a party to, and agrees that, on or after the date of this Agreement, the Investor
shall not (and shall cause its Controlled Affiliates and use commercially reasonable efforts to cause any Non-Controlled Affiliates
not to) enter into any agreement that conflicts with the rights granted to the Company in this Agreement.


 


(Signature Page Follows)


 




    	 



     


    

 


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IN WITNESS WHEREOF, the parties have
executed and delivered this Agreement as of the date first above written.


 


	 	COMPANY:
	 	 
	 	CLEARSIGN COMBUSTION CORPORATION
	 	 
	 	By:	 
	 	Name: 	 
	 	Title:	 
	 	 
	 	INVESTOR:
	 	 
	 	 CLIRSPV, LLC
	 	 
	 	By:	 
	 	Name: 	 
	 	Title:	 






 



    	 



     


    




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APPENDIX III


  


REGISTRATION RIGHTS AGREEMENT


 


This Registration Rights Agreement (this
“Agreement”) is made and entered into as of July __, 2018 by and between ClearSign Combustion Corporation (the
“Company”), and CLIRSPV, LLC, a Delaware limited liability company (the “Purchaser”).


 


RECITAL


 


This Agreement is made pursuant to the Stock
Purchase Agreement, dated as of July __, 2018, between the Company and the Purchaser (the “Purchase Agreement”).


 


AGREEMENT


 


NOW, THEREFORE, IN CONSIDERATION of
the mutual covenants contained in this Agreement, and for other good and valuable consideration the receipt and adequacy of which
are hereby acknowledged, the Company and the Purchaser agree as follows:


 


SECTION 1.


DEFINITIONS


 


Capitalized terms used and not otherwise
defined herein that are defined in the Purchase Agreement shall have the meanings given such terms in the Purchase Agreement. 
As used in this Agreement, the following terms shall have the respective meanings set forth in this Section 1:


 


“Advice” shall have the
meaning set forth in Section 7(b).


 


“Affiliate” means, with
respect to any Person, any other Person that, directly or indirectly through one or more intermediaries, Controls, is controlled
by or is under common control with such Person, as such terms are used in and construed under Rule 405 under the Securities
Act.


  


“Control” (including
the terms “controlling”, “controlled by” or “under common control with”) means the possession,
direct or indirect, of the power to direct or cause the direction of the management and policies of a Person, whether through the
ownership of voting securities, by contract or otherwise.


 


“Commission” means the
United States Securities and Exchange Commission, or any successor entity or entities, including, if applicable, the staff of the
Commission.


 


“Common Stock” means
the common stock, par value $0.0001 per share, of the Company.


 


“Effectiveness Date”
means: (a) with respect to the Initial Registration Statement required to be filed hereunder, the date of that is six months
after the date of this Agreement and (b) with respect to any additional Registration Statements which may be required pursuant
to Section 2, the earlier to occur of (i) the 90th day following the date on which the Company first knows, or reasonably
should have known, that such additional Registration Statement is required under such Section (or the 120th day following
such date in the event such additional Registration Statement is reviewed by the Commission) and (ii) the 5th Trading
Day after the date the Company is notified (orally or in writing, whichever is earlier) by the Commission that such Registration
Statement will not be “reviewed” or will not be subject to further review. If the Effectiveness Date falls on a Saturday,
Sunday or other date that the Commission is closed for business, the Effectiveness Date shall be extended to the next day on which
the Commission is open for business.  The Effectiveness Date for a Registration Statement shall be extended without default
hereunder in the event that the Company’s failure to obtain the effectiveness of the Registration Statement on a timely basis
results from the failure of the Holder to timely provide the Company with information requested by the Company and necessary
to complete the Registration Statement in accordance with the requirements of the Securities Act (in which the Effectiveness Date
would be extended with respect to Registrable Securities held by such Holder).


 




     


     


    

 


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“Effectiveness Period”
shall have the meaning set forth in Section 2(a).


 


“Exchange Act” means
the Securities Exchange Act of 1934, as amended.


 


“Filing Date” means:
(a) with respect to the Initial Registration Statement, the 3 month anniversary of the Closing Date, and (b) with respect
to any additional Registration Statements that may be required pursuant to Section 2 hereof, the 45th day following the
date on which the Company first knows, or reasonably should have known, that such additional Registration Statement is required
under such Section.


 


“Holder” or “Holders”
means a holder from time to time of Registrable Securities, but only if such holder is the Purchaser or any assignee thereof in
accordance with Section 7(j).


 


“Indemnified Party” shall
have the meaning set forth in Section 6(c).


 


“Indemnifying Party”
shall have the meaning set forth in Section 6(c).


 


“Initial Registration Statement”
shall mean the initial Registration Statement required to be filed to cover the resale by the Purchaser of the Registrable Securities
pursuant to Section 2(a).


 


“Losses” shall have the
meaning set forth in Section 6(a).


  


“Person” means an individual
or corporation, partnership, trust, incorporated or unincorporated association, joint venture, limited liability company, joint
stock company, government (or an agency or subdivision thereof) or other entity of any kind.


  


“Proceeding” means an
action, claim, suit, investigation or proceeding (including, without limitation, an investigation or partial proceeding, such as
a deposition), whether commenced or threatened.


 


“Prospectus” means the
prospectus included in a Registration Statement (including, without limitation, a prospectus that includes any information previously
omitted from a prospectus filed as part of an effective registration statement in reliance upon Rule 430A or Rule 430B
promulgated by the Commission pursuant to the Securities Act), as amended or supplemented by any prospectus supplement, with respect
to the terms of the offering of any portion of the Registrable Securities covered by a Registration Statement, and all other amendments
and supplements to the Prospectus, including post-effective amendments, and all material incorporated by reference or deemed to
be incorporated by reference in such Prospectus.


 


“Reduction Securities”
shall have the meaning set forth in Section 2(b).


 


“Registrable Securities”
means (i) the Shares issued pursuant to the Purchase Agreement including any shares issued pursuant to the Purchase Right
and, in the case of the Participation Right only, so long as the shares purchased by other investors in the offering subject to
the Participation Right are also required to be registered and (ii) any other shares of Common Stock issued as (or issuable
upon conversion or exercise of any warrant, right or other security which is issued as) a dividend or other distribution with respect
to, in exchange for or in replacement of the Shares; provided, however, that any such Registrable Securities shall cease to be
Registrable Securities (and the Company shall not be required to maintain the effectiveness of any, or file another, Registration
Statement hereunder with respect thereto) for so long as (a) a Registration Statement with respect to the sale of such Registrable
Securities is declared effective by the Commission under the Securities Act and such Registrable Securities have been disposed
of by the Holder in accordance with such effective Registration Statement, (b) such Registrable Securities have been previously
sold in accordance with Rule 144, (c) such Registrable Securities become eligible for resale without volume or manner-of-sale
restrictions and without current public information pursuant to Rule 144, as reasonably determined by the Company, based upon
the advice of counsel to the Company, (d) such Registrable Securities have been sold, transferred or otherwise disposed of
by a Person in a transaction in which its rights under this Agreement were not assigned in accordance with Section 7(j), or
(e) such Registrable Securities cease to be outstanding.


 




     


     


    

 


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“Registration Statement”
means each of the following: (i) an initial registration statement which is required to register the resale of the Registrable
Securities, and (ii) each additional registration statement, if any, contemplated by Section 2, and including, in each
case, the Prospectus, amendments and supplements to each such registration statement or Prospectus, including pre- and post-effective
amendments, all exhibits thereto, and all material incorporated by reference or deemed to be incorporated by reference in such
registration statement.


 


“Rule 144” means
Rule 144 promulgated by the Commission pursuant to the Securities Act, as such Rule may be amended from time to time,
or any similar rule or regulation hereafter adopted by the Commission having substantially the same effect as such Rule.


 


“Rule 415” means
Rule 415 promulgated by the Commission pursuant to the Securities Act, as such Rule may be amended from time to time,
or any similar rule or regulation hereafter adopted by the Commission having substantially the same effect as such Rule.


  


“Rule 424” means
Rule 424 promulgated by the Commission pursuant to the Securities Act, as such Rule may be amended from time to time,
or any similar rule or regulation hereafter adopted by the Commission having substantially the same effect as such Rule.


 


“SEC Guidance” means
(i) any publicly-available written guidance of the Commission staff, (ii) any oral guidance, comments, requirements or
requests of the Commission staff, in each case given or directed specifically to the Company, and (iii) the Securities Act.


 


“Securities Act” means
the Securities Act of 1933, as amended.


 


“Shares” shall have the
meaning set forth in the Purchase Agreement and shall include shares of Common Stock purchased by the Purchaser pursuant to the
Purchase Right and the Participation Right, and, in the case of the Participation Right only, so long as the shares purchased by
other investors in the offering subject to the Participation Right are also required to be registered.


 


“Trading Day” means any
day on which the Common Stock is traded on the Nasdaq Capital Market, or, if the Nasdaq Capital Market is not the principal trading
market for the Common Stock, then on the principal securities exchange or securities market on which the Common Stock is then traded.


 


“Transaction Documents”
shall have the meaning set forth in the Purchase Agreement.


  


SECTION 2.


REGISTRATION


 


(a)       
On or prior to each Filing Date, the Company shall prepare and file with the Commission a Registration Statement covering the resale
of all of the Registrable Securities that are not then registered on an existing and effective Registration Statement for an offering
to be made on a continuous basis pursuant to Rule 415.  The Registration Statement filed hereunder shall be on Form S-3
(except if the Company is not then eligible to register for resale the Registrable Securities on Form S-3, in which case such
registration shall be on another appropriate form in accordance herewith) and shall contain (except if otherwise required pursuant
to written comments received from the Commission upon a review of such Registration Statement) the “Plan of Distribution”
in substantially the form attached hereto as Annex A.  The Company shall use its commercially reasonable efforts to
cause a Registration Statement filed under this Agreement to be declared effective under the Securities Act no later than the Effectiveness
Date for such Registration Statement, and shall, subject Section 7(b) hereof, use its commercially reasonable efforts
to keep the Registration Statement continuously effective under the Securities Act until the date on which all securities under
such Registration Statement have ceased to be Registrable Securities (the “Effectiveness Period”).  It
is agreed and understood that the Company shall, from time to time, be obligated to file one or more additional Registration Statements
to cover any Registrable Securities which are not registered for resale pursuant to a pre-existing Registration Statement.


 




     


     


    

 


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(b)       Notwithstanding
anything contained herein to the contrary, in the event that the Commission limits the amount of Registrable Securities that may
be included and sold by the Holder in any Registration Statement, including the Initial Registration Statement, pursuant to Rule 415
or any other basis (and notwithstanding that the Company used commercially reasonable efforts to advocate with the Commission where
practicable for the registration of all or a greater number of Registrable Securities), the Company may reduce the number of Registrable
Securities included in such Registration Statement on behalf of such Holder in whole or in part (in case of an exclusion as to
a portion of such Registrable Securities, such portion shall be allocated pro rata among multiple Holders in proportion to the
respective numbers of Registrable Securities represented by Shares requested to be registered by each such Holder over the total
amount of Registrable Securities represented by Shares) (such Registrable Securities, the “Reduction Securities”). 
Any reduction of Registrable Securities pursuant to this Section 2(b) shall occur only after all securities that are
not Registrable Securities, if any, are first removed from such Registration Statement where permitted under contractual arrangements
between the Company and the holders of such other securities (provided that the Company first uses commercially reasonable efforts
(which efforts shall not require the Company to pay money or issue additional securities to the holders) to obtain waivers under
such contractual arrangements of stockholders’ rights to have such securities included in such Registration Statement). 
In such event, the Company shall give the Holder prompt notice of the number of such Reduction Securities excluded and the Company
will not be liable for any damages under this Agreement in connection with the exclusion of such Reduction Securities.  The
Company shall use its commercially reasonable efforts at the first opportunity that is permitted by the Commission to register
for resale the Reduction Securities.  Such new Registration Statement shall be on Form S-3 (except if the Company is
not then eligible to register for resale the Reduction Securities on Form S-3, in which case such registration shall be on
another appropriate form for such purpose) and shall contain (except if otherwise required pursuant to written comments received
from the Commission upon a review of such Registration Statement) the “Plan of Distribution” in substantially the form
attached hereto as Annex A.  The Company shall use its commercially reasonable efforts to cause each such Registration
Statement to be declared effective under the Securities Act as soon as possible but, in any event, no later than the Effectiveness
Date, and shall use its commercially reasonable efforts to keep such Registration Statement continuously effective under the Securities
Act during the entire Effectiveness Period, subject to Section 7(b) hereof.


 


(c)       No
Holder shall be named as an “underwriter” in any Registration Statement without such Holder’s prior written consent,
except if required pursuant to written comments received from the Commission upon a review of such Registration Statement; provided,
however, that prior to naming a Holder as an underwriter in any Registration Statement, (i) the Company shall use its commercially
reasonable efforts to advocate with the Commission against naming such Holder as an underwriter in accordance with Commission rules and
regulations and SEC Guidance and (ii) if, despite the Company’s commercially reasonable efforts to advocate with the
Commission against naming such Holder as an underwriter, the Commission continues to require that such Holder be named as an underwriter
in any Registration Statement, such Holder shall have the right (but not the obligation), prior to being so named, without any
penalty to the Company, to either (A) remove itself from such Registration Statement or (B) reduce its number of Registrable
Securities included in such Registration Statement such that it shall no longer be required to be named as an underwriter in such
Registration Statement.


 


(d)       Unless
contractually obligated to do so (provided that the Company first uses commercially reasonable efforts (which efforts shall not
require the Company to pay money or issue additional securities to the holders) to obtain waivers under such contractual arrangements
of stockholders’ rights to have such securities included in such Registration Statement), in no event shall the Company include
any securities other than the Registrable Securities on any Registration Statement without the prior written consent of Holders
of a majority of the Registrable Securities.


 


(e)       The
disposition of Registrable Securities from any Registration Statement may occur in one or more underwritten offerings, block transactions,
broker transactions, at-market transactions or in such other manner or manners as may be specified by the Holders in accordance
with applicable law.


 


(f)       In
the event that Form S-3 is not available for the registration of the resale of Registrable Securities hereunder, the
Company shall (i) register the resale of the Registrable Securities on another appropriate form and (ii) undertake to
register the Registrable Securities on Form S-3 promptly after such form is available, provided that the Company shall
maintain the effectiveness of the Registration Statement then in effect until such time as a Registration Statement on Form S-3
covering the Registrable Securities has been declared effective by the Commission.


 




     


     


    

 


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SECTION 3.


REGISTRATION PROCEDURES


 


In connection with the Company’s registration
obligations hereunder, the Company shall:


 


(a)       
Not less than three Trading Days prior to the filing of a Registration Statement or any related Prospectus or any amendment or
supplement thereto, the Company shall furnish to the Holder copies of all such documents proposed to be filed (other than those
incorporated by reference).  Notwithstanding the foregoing, the Company shall not be required to furnish to the Holder any
prospectus supplement being prepared and filed solely to name new or additional selling securityholders unless such Holder is named
in such prospectus supplement.  In addition, in the event that any Registration Statement is on a form which does not permit
incorporation by reference), the Company shall not be required to furnish to the Holder any prospectus supplement containing information
included in a report or proxy statement filed under the Exchange Act that would be incorporated by reference in such Registration
Statement if such Registration Statement were on Form S-3 (or other form which permits incorporation by reference). 
The Company shall duly consider any comments made by the Holder and received by the Company not later than two Trading Days prior
to the filing of the Registration Statement, but shall not be required to accept any such comments to which it reasonably objects.


 


(b)       (i) 
Prepare and file with the Commission such amendments, including post-effective amendments, to each Registration Statement and the
Prospectus used in connection therewith as may be necessary to keep such Registration Statement continuously effective as to the
applicable Registrable Securities for its Effectiveness Period and prepare and file with the Commission such additional Registration
Statements in order to register for resale under the Securities Act all of the Registrable Securities; (ii) cause the related
Prospectus to be amended or supplemented by any required Prospectus supplement, and as so supplemented or amended to be filed pursuant
to Rule 424; (iii) respond as promptly as reasonably possible to any comments received from the Commission with respect
to each Registration Statement or any amendment thereto and, as promptly as reasonably possible notify the Holder of such comments
and, upon the request of such Holder, provide the Holder true and complete copies of all correspondence from and to the Commission
relating to such Registration Statement that pertains to the Holder as a Selling Stockholder; and (iv) comply in all material
respects with the provisions of the Securities Act and the Exchange Act with respect to the Registration Statements and the disposition
of all Registrable Securities covered by each Registration Statement.


 


(c)       
Notify the Holder as promptly as reasonably possible (and, in the case of (i)(A) below, not less than three Trading Days prior
to such filing) and (if requested by any such Person) confirm such notice in writing no later than one Trading Day following the
day: (i)(A) when a Prospectus or any prospectus supplement (but only to the extent notice is required under Section 3(a) above)
or post-effective amendment to a Registration Statement is proposed to be filed; (B) when the Commission notifies the Company
whether there will be a “review” of such Registration Statement and whenever the Commission comments in writing on
such Registration Statement (in which case the Company shall provide true and complete copies thereof and all written responses
thereto to each of the Holders that pertain to such Holder as a Selling Stockholder or to the Plan of Distribution upon the request
of such Holder); and (C) with respect to each Registration Statement or any post-effective amendment, when the same has been
declared effective; (ii) of any request by the Commission or any other Federal or state governmental authority for amendments
or supplements to a Registration Statement or Prospectus or for additional information that pertains to the Holder as a Selling
Stockholder or the Plan of Distribution; (iii) of the issuance by the Commission of any stop order suspending the effectiveness
of a Registration Statement covering any or all of the Registrable Securities or the initiation of any Proceedings for that purpose;
(iv) of the receipt by the Company of any notification with respect to the suspension of the qualification or exemption from
qualification of any of the Registrable Securities for sale in any jurisdiction, or the initiation or threatening of any Proceeding
for such purpose; (v) of the occurrence of any event or passage of time that makes the financial statements included or incorporated
by reference in a Registration Statement ineligible for inclusion or incorporation by reference therein or any statement made in
such Registration Statement or Prospectus or any document incorporated or deemed to be incorporated therein by reference untrue
in any material respect or that requires any revisions to such Registration Statement, Prospectus or other documents so that, in
the case of such Registration Statement or the Prospectus, as the case may be, it will not contain any untrue statement of a material
fact or omit to state any material fact required to be stated therein or necessary to make the statements therein, in light of
the circumstances under which they were made, not misleading; and (vi) of the occurrence or existence of any pending corporate
development with respect to the Company that the Company in good faith believes may be material and that, in the determination
of the Company, makes it not in the best interest of the Company to allow continued availability of a Registration Statement or
Prospectus.


 




     


     


    

 


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(d)       
Use its reasonable best efforts to avoid the issuance of, or, if issued, obtain the withdrawal of (i) any order suspending
the effectiveness of a Registration Statement, or (ii) any suspension of the qualification (or exemption from qualification)
of any of the Registrable Securities for sale in any jurisdiction, at the earliest practicable moment.


 


(e)       
Furnish to the Holder, without charge, at least one conformed copy of each Registration Statement and each amendment thereto and
all exhibits to the extent reasonably requested by such Person (including those previously furnished or incorporated by reference)
promptly after the filing of such documents with the Commission; provided, that the Company shall have no obligation to
provide any document pursuant to this clause that is available on the EDGAR system.


 


(f)       
Promptly deliver to the Holder, without charge, as many copies of each Prospectus or Prospectuses (including each form of prospectus)
and each amendment or supplement thereto as such Person may reasonably request.  Subject to Section 7(b) hereof,
the Company hereby consents to the use of such Prospectus and each amendment or supplement thereto by each of the selling Holders
in connection with the offering and sale of the Registrable Securities covered by such Prospectus and any amendment or supplement
thereto.


 


(g)       
Prior to any public offering of Registrable Securities, use its commercially reasonable efforts to register or qualify or cooperate
with the selling Holder in connection with the registration or qualification (or exemption from such registration or qualification)
of such Registrable Securities for offer and sale under the securities or Blue Sky laws of those jurisdictions within the United
States as such Holder reasonably requests in writing to keep each such registration or qualification (or exemption therefrom) effective
during the Effectiveness Period and to do any and all other acts or things necessary or advisable to enable the disposition in
such jurisdictions of the Registrable Securities covered by the Registration Statements; provided, that the Company shall
not be required to qualify generally to do business in any jurisdiction where it is not then so qualified or subject the Company
to any material tax in any such jurisdiction where it is not then so subject.


 


(h)       
Cooperate with the Holder to facilitate the timely preparation and delivery of certificates representing Registrable Securities
to be delivered to a transferee pursuant to the Registration Statements, which certificates shall be free, to the extent permitted
by the Purchase Agreement, of all restrictive legends, and to enable such Registrable Securities to be in such denominations and
registered in such names as the Holder may request.


 


(i)       
Upon the occurrence of any event contemplated by Section 3(c)(v), as promptly as reasonably possible, prepare a supplement
or amendment, including a post-effective amendment, to the affected Registration Statements or a supplement to the related Prospectus
or any document incorporated or deemed to be incorporated therein by reference, and file any other required document so that, as
thereafter delivered, no Registration Statement nor any Prospectus will contain an untrue statement of a material fact or omit
to state a material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances
under which they were made, not misleading.


 


(j)       
The Company may require the selling Holder to furnish to the Company a certified statement as to the number of shares of Common
Stock beneficially owned by such Holder and any Affiliate thereof, the natural persons, if any, thereof that have voting and dispositive
control over the shares and any other information with respect to such Holder as the Commission requests.


  




     


     


    

 


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(k)       
Make available at reasonable times for inspection by any Holder, any managing underwriter participating in any disposition of such
Registrable Securities pursuant to a Registration Statement, Holders’ legal counsel and any attorney, accountant or other
agent retained by any such Holder or any managing underwriter (each, an “Inspector” and collectively, the “Inspectors”),
all financial and other records, pertinent corporate documents and properties of the Company and its subsidiaries (collectively,
the “Records”) as shall be reasonably necessary to enable them to exercise their due diligence responsibility,
and cause the Company’s and its subsidiaries’ officers, directors and employees, and the independent public accountants
of the Company, to supply all information reasonably requested by any such Inspector in connection with such Registration Statement.
Notwithstanding the foregoing, Records and other information that the Company determines, in good faith, to be confidential and
which it notifies the Inspectors are confidential shall not be disclosed by the Inspectors or used for any purpose other than as
necessary or appropriate for the purpose of such inspection (and the Inspectors shall confirm their agreement in writing in advance
to the Company if the Company shall so request) unless (i) the disclosure of such Records is necessary, in the Company’s
judgment, to avoid or correct a misstatement or omission in the Registration Statement, (ii) the release of such Records is
ordered pursuant to a subpoena or other order from a court of competent jurisdiction after exhaustion of all appeals therefrom
or (iii) the information in such Records was known to the Inspectors on a non-confidential basis prior to its disclosure by
the Company or has been made generally available to the public. Each Holder agrees that it shall promptly, upon learning that disclosure
of such Records is sought in a court of competent jurisdiction, give notice to the Company and allow the Company, at the Company’s
expense, to undertake appropriate action to prevent disclosure of the Records deemed confidential, and such Holder shall reasonably
cooperate with the Company in connection therewith.


 


(l)       If
such sale is pursuant to an underwritten offering, (i) obtain “comfort” letters dated the pricing and closing
dates of such offering under the underwriting agreement from the Company’s independent public accountants in customary form
and covering such matters of the type customarily covered by “comfort” letters as Holders’ legal counsel or the
managing underwriter reasonably requests; (ii) enter into a customary underwriting agreement with the underwriter containing
customary representations and warranties, covenants and legal opinions addressed to the underwriters; (iii) take other such
actions as reasonably required in order to expedite or facilitate the disposition of such Registrable Securities, including causing
its officers to participate in “road shows” and other information meetings organized by the underwriters, if applicable,
of reasonable and customary duration and frequency (but not to exceed three days in each instance); or (iv) deliver such documents
and certificates as may be reasonably requested and as are customarily delivered in similar offerings.


 


(m)       
Comply with all applicable rules and regulations of the SEC, and make generally available to its security holders, as soon
as reasonably practicable but no later than fifteen (15) months after the effective date of the Registration Statement, an earnings
statement covering a period of twelve (12) months beginning after the effective date of the Registration Statement, in a manner
which satisfies the provisions of Section 11(a) of the Securities Act and Rule 158 thereunder.


 


(n)       
Cause all such Registrable Securities to be listed on each securities exchange on which similar securities issued by the Company
are then listed.


  


(o)       
Provide reasonable cooperation to each seller of Registrable Securities and each underwriter participating in the disposition of
such Registrable Securities and their respective counsel in connection with any filings required to be made with the Financial
Industry Regulatory Authority (“FINRA”) pursuant to FINRA Rule 5110 as requested by such Holder.


 


SECTION 4.


HOLDER’S OBLIGATIONS


 


The Holder agrees, by acquisition of the
Registrable Securities, that the Holder shall not be entitled to sell any of such Registrable Securities pursuant to a Registration
Statement or to receive a Prospectus relating thereto, unless such Holder has furnished the Company with all material information
required to be set forth in the Purchaser Questionnaire and Selling Stockholder Questionnaire attached hereto as Annex B . 
Any sale of any Registrable Securities by any Holder shall constitute a representation and warranty by such Holder that the information
regarding such Holder is as set forth in the Prospectus delivered by such Holder in connection with such disposition, and that
such Prospectus does not as of the time of such sale contain any untrue statement of a material fact regarding such Holder or omit
to state any material fact regarding such Holder necessary to make the statements in such Prospectus, in the light of the circumstances
under which they were made, not misleading, solely to the extent such facts are based upon information regarding such Holder furnished
in writing to the Company by such Holder for use in such Prospectus.


 




     


     


    

 


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SECTION 5.


REGISTRATION EXPENSES


 


All fees and expenses incident to the Company’s
performance of or compliance with its obligations under this Agreement shall be borne by the Company whether or not any Registrable
Securities are sold pursuant to a Registration Statement.  The fees and expenses referred to in the foregoing sentence shall
include, without limitation, (i) all registration and filing fees (including, without limitation, fees and expenses (A) with
respect to filings required to be made with the principal trading market on which the Common Stock is then listed for trading,
(B) in compliance with applicable state securities or Blue Sky laws) and (C) if not previously paid by the Company in
connection with an issuer filing, with respect to any filing that may be required to be made by any broker through which a Holder
intends to make sales of Registrable Securities with FINRA pursuant to FINRA Rule 5110, so long as the broker is receiving
no more than a customary brokerage commission in connection with such sale, (ii) printing expenses (including, without limitation,
expenses of printing certificates for Registrable Securities and of printing prospectuses if the printing of prospectuses is reasonably
requested by the holders of a majority of the Registrable Securities included in the Registration Statement), (iii) messenger,
telephone and delivery expenses, (iv) reasonable fees and disbursements of counsel for the Company, (v) Securities Act
liability insurance, if the Company so desires such insurance, and (vi) reasonable fees and expenses of all other Persons
retained by the Company in connection with the consummation of the transactions contemplated by this Agreement.  In addition,
the Company shall be responsible for all of its internal expenses incurred in connection with the consummation of the transactions
contemplated by this Agreement (including, without limitation, all salaries and expenses of its officers and employees performing
legal or accounting duties), the expense of any annual audit and the fees and expenses incurred in connection with the listing
of the Registrable Securities on any securities exchange as required hereunder.  The Holder shall bear the cost of all underwriting
discounts and selling commissions associated with any sale of Registrable Securities and shall pay all of its own costs and expenses,
including, without limitation, all fees and disbursements to counsel (and any other advisors) of the Holder and any stock transfer
taxes.  In no event shall the Company be responsible for any broker or similar commissions of any Holder.


 


SECTION 6.


INDEMNIFICATION


 


(a)       
Indemnification by the Company.  The Company shall, notwithstanding any termination of this Agreement, indemnify
and hold harmless the Holder, the officers, directors, agents, partners, members, stockholders and employees of such Holder, each
Person who controls such Holder (within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange
Act) and the officers, directors, agents, partners, members, stockholders and employees of each such controlling Person, to the
fullest extent permitted by applicable law, from and against any and all losses, claims, damages, liabilities, costs (including,
without limitation, reasonable costs of preparation and reasonable attorneys’ fees) and expenses (collectively, “Losses”),
as incurred, arising out of or relating to any untrue or alleged untrue statement of a material fact contained in any Registration
Statement, any Prospectus or any form of prospectus or in any amendment or supplement thereto (it being understood that the Holder
has approved Annex A hereto for this purpose), or arising out of or relating to any omission or alleged omission of a material
fact required to be stated therein or necessary to make the statements therein (in the case of any Prospectus or form of prospectus
or supplement thereto, in light of the circumstances under which they were made) not misleading, except to the extent, but only
to the extent, that (1) such untrue statements, alleged untrue statements, omissions or alleged omissions are based solely
upon information regarding such Holder furnished in writing to the Company by such Holder expressly for use therein, or to the
extent that such information relates to such Holder or such Holder’s proposed method of distribution of Registrable Securities
and was reviewed and expressly approved in writing by such Holder expressly for use in the Registration Statement, such Prospectus
or such form of Prospectus or in any amendment or supplement thereto (it being understood that the Holder has approved Annex
A hereto for this purpose) or (2) in the case of an occurrence of an event of the type specified in Section 3(c)(ii)-(v),
the use by such Holder of an outdated or defective Prospectus after the Company has validly notified such Holder in writing (in
accordance with Section 7(b) below) that the Prospectus is outdated or defective and prior to the receipt by such Holder
of an Advice (as defined below) or an amended or supplemented Prospectus, but only if and to the extent that following the receipt
of the Advice or the amended or supplemented Prospectus the misstatement or omission giving rise to such Loss would have been corrected. 
The Company shall notify the Holder promptly of the institution, threat or assertion of any Proceeding of which the Company is
aware in connection with the transactions contemplated by this Agreement.


 




     


     


    

 


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(b)       
Indemnification by Holder.  The Holder shall, notwithstanding any termination of this Agreement, severally and
not jointly, indemnify and hold harmless the Company, its directors, officers, agents and employees, each Person who controls the
Company (within the meaning of Section 15 of the Securities Act and Section 20 of the Exchange Act), and the directors,
officers, agents, partners, members, stockholders or employees of such controlling Persons, to the fullest extent permitted by
applicable law, from and against all Losses, as incurred, arising solely out of or based solely upon: (x) for so long as the
prospectus delivery requirements of the Securities Act apply to sales by such Holder, such Holder’s failure to comply with
the prospectus delivery requirements of the Securities Act or (y) any untrue statement of a material fact contained in any
Registration Statement, any Prospectus, or any form of prospectus, or in any amendment or supplement thereto, or arising solely
out of or based solely upon any omission of a material fact required to be stated therein or necessary to make the statements therein
(in the case of any Prospectus, or any form of prospectus or supplement thereto, in light of the circumstances under which they
were made) not misleading to the extent, but only to the extent that, (1) such untrue statements or omissions are based solely
upon information regarding such Holder furnished in writing to the Company by such Holder expressly for use therein, or to the
extent that such information relates to such Holder or such Holder’s proposed method of distribution of Registrable Securities
and was reviewed and expressly approved in writing by such Holder expressly for use in the Registration Statement, such Prospectus
or such form of Prospectus or in any amendment or supplement thereto (it being understood that the Holder has approved Annex A
hereto for this purpose) or (2) in the case of an occurrence of an event of the type specified in Section 3(c)(ii)-(v),
the use by such Holder of an outdated or defective Prospectus after the Company has validly notified such Holder in writing (in
accordance with Section 7(b) below) that the Prospectus is outdated or defective and prior to the receipt by such Holder of an
Advice or an amended or supplemented Prospectus, but only if and to the extent that following the receipt of the Advice or the
amended or supplemented Prospectus the misstatement or omission giving rise to such Loss would have been corrected.  In no
event shall the liability of any selling Holder hereunder be greater in amount than the dollar amount of the net proceeds received
by such Holder upon the sale of the Registrable Securities giving rise to such indemnification obligation.


 


(c)       
Conduct of Indemnification Proceedings.  If any Proceeding shall be brought or asserted against any Person entitled
to indemnity hereunder (an “Indemnified Party”), such Indemnified Party shall promptly notify the Person from
whom indemnity is sought (the “Indemnifying Party”) in writing, and the Indemnifying Party shall assume the
defense thereof, including the employment of counsel reasonably satisfactory to the Indemnified Party and the payment of all fees
and expenses incurred in connection with defense thereof; provided, that the failure of any Indemnified Party to give such notice
shall not relieve the Indemnifying Party of its obligations or liabilities pursuant to this Agreement, except (and only) to the
extent that it shall be finally determined by a court of competent jurisdiction (which determination is not subject to appeal or
further review) that such failure shall have proximately and materially adversely prejudiced the Indemnifying Party.


 


An Indemnified Party shall have the right
to employ separate counsel in any such Proceeding and to participate in the defense thereof, but the fees and expenses of such
counsel shall be at the expense of such Indemnified Party or Parties unless:  (1) the Indemnifying Party has agreed in
writing to pay such fees and expenses; (2) the Indemnifying Party shall have failed promptly to assume the defense of such
Proceeding and to employ counsel reasonably satisfactory to such Indemnified Party in any such Proceeding; or (3) the named
parties to any such Proceeding (including any impleaded parties) include both such Indemnified Party and the Indemnifying Party,
and such Indemnified Party shall have been advised by counsel that a conflict of interest is likely to exist if the same counsel
were to represent such Indemnified Party and the Indemnifying Party (in which case, if such Indemnified Party notifies the Indemnifying
Party in writing that it elects to employ separate counsel at the expense of the Indemnifying Party, the Indemnifying Party shall
not have the right to assume the defense thereof and such counsel shall be at the expense of the Indemnifying Party); provided,
that the Indemnifying Party shall not be liable for the fees and expenses of more than one separate firm of attorneys at any time
for all Indemnified Parties pursuant to this Section 6(c).  The Indemnifying Party shall not be liable for any settlement
of any such Proceeding effected without its written consent, which consent shall not be unreasonably withheld.  No Indemnifying
Party shall, without the prior written consent of the Indemnified Party, effect any settlement of any pending Proceeding in respect
of which any Indemnified Party is a party, unless such settlement includes an unconditional release of such Indemnified Party from
all liability on claims that are the subject matter of such Proceeding. Each Indemnified Party shall furnish such information regarding
itself or the claim in question as an Indemnifying Party may reasonably request in writing and as shall be reasonably required
in connection with defense of such claim and litigation resulting therefrom.


 




     


     


    

 


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All fees and expenses of the Indemnified Party
(including reasonable fees and expenses to the extent incurred in connection with investigating or preparing to defend such Proceeding
in a manner not inconsistent with this Section) shall be paid to the Indemnified Party, as incurred, within ten Trading Days of
written notice thereof to the Indemnifying Party (regardless of whether it is ultimately determined that an Indemnified Party is
not entitled to indemnification hereunder; provided, that the Indemnifying Party may require such Indemnified Party to undertake
to reimburse all such fees and expenses to the extent it is finally judicially determined that such Indemnified Party is not entitled
to indemnification hereunder).


 


(d)       
Contribution.  If a claim for indemnification under Section 6(a) or Section 6(b) is unavailable
to an Indemnified Party (by reason of public policy or otherwise), then each Indemnifying Party, in lieu of indemnifying such Indemnified
Party, shall contribute to the amount paid or payable by such Indemnified Party as a result of such Losses, in such proportion
as is appropriate to reflect the relative fault of the Indemnifying Party and Indemnified Party in connection with the actions,
statements or omissions that resulted in such Losses as well as any other relevant equitable considerations.  The relative
fault of such Indemnifying Party and Indemnified Party shall be determined by reference to, among other things, whether any action
in question, including any untrue or alleged untrue statement of a material fact or omission or alleged omission of a material
fact, has been taken or made by, or relates to information supplied by, such Indemnifying Party or Indemnified Party, and the parties’
relative intent, knowledge, access to information and opportunity to correct or prevent such action, statement or omission. 
The amount paid or payable by a party as a result of any Losses shall be deemed to include, subject to the limitations set forth
in Section 6(c), any reasonable attorneys’ or other reasonable fees or expenses incurred by such party in connection
with any Proceeding to the extent such party would have been indemnified for such fees or expenses if the indemnification provided
for in this Section was available to such party in accordance with its terms.


 


The parties hereto agree that it would not
be just and equitable if contribution pursuant to this Section 6(d) were determined by pro rata allocation or by any
other method of allocation that does not take into account the equitable considerations referred to in the immediately preceding
paragraph.  Notwithstanding the provisions of this Section 6(d), no Holder shall be required to contribute, in the aggregate,
any amount in excess of the amount by which the proceeds actually received by such Holder from the sale of the Registrable Securities
subject to the Proceeding exceeds the amount of any damages that such Holder has otherwise been required to pay by reason of such
untrue or alleged untrue statement or omission or alleged omission.  No person guilty of fraudulent misrepresentation (within
the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty
of such fraudulent misrepresentation.


 


The indemnity and contribution agreements
contained in this Section 6 are in addition to any liability that the Indemnifying Parties may have to the Indemnified Parties
and are not in diminution or limitation of the indemnification provisions under the Purchase Agreement.


 


SECTION 7.


MISCELLANEOUS


 


(a)       
Piggy-Back Registrations.  If at any time during the Effectiveness Period, except as contemplated by Section 2(b) hereof,
there is not an effective Registration Statement covering all of the Registrable Securities and the Company shall determine to
prepare and file with the Commission a registration statement relating to an offering for its own account or the account of others
under the Securities Act of any of its equity securities, other than on Form S-4 or Form S-8 (each as promulgated under
the Securities Act) or their then equivalents relating to equity securities to be issued solely in connection with any acquisition
of any entity or business or equity securities issuable in connection with the stock option or other employee benefit plans, then
the Company shall send to each Holder a written notice of such determination and, if within 15 days after the date of such notice,
any such Holder shall so request in writing, the Company shall include in such registration statement all or any part of such Registrable
Securities such Holder requests to be registered; provided, however, that the Company shall not be required to register
any Registrable Securities pursuant to this Section 7(a) that are eligible for resale pursuant to Rule 144 promulgated
under the Securities Act without volume limitation and without current public information or that are the subject of a then effective
Registration Statement; provided, further, however, if there is not an effective Registration Statement covering all of the Registrable
Securities during the Effectiveness Period, the Company may file a registration statement with the Commission to register equity
securities of the Company to be sold on a primary basis, provided that the Company does not sell any such shares until there is
an effective Registration Statement covering all of the Registrable Securities. The Company shall have the right to terminate or
withdraw any registration initiated by it under this Section 7(a) prior to the effectiveness of such registration whether
or not the Holder has elected to include securities in such registration.


 




     


     


    

 


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(b)       
Discontinued Disposition.  The Holder agrees by its acquisition of such Registrable Securities that, upon receipt
of a notice from the Company of the occurrence of any event of the kind described in Section 3(c)(ii)-(vi), such Holder will
forthwith discontinue disposition of such Registrable Securities under the Registration Statement until such Holder’s receipt
of the copies of the supplemented Prospectus and/or amended Registration Statement or until it is advised in writing (the “Advice”)
by the Company that the use of the applicable Prospectus may be resumed, and, in either case, has received copies of any additional
or supplemental filings that are incorporated or deemed to be incorporated by reference in such Prospectus or Registration Statement;
provided that, with respect to the events described in Sections 3(c)(v) and 3(c)(vi), the Company shall not be entitled to
suspend the effectiveness or use of such Registration Statement for an aggregate of more than 45 consecutive Trading Days or an
aggregate of 90 Trading Days (which need not be consecutive) in any given 360-day period. The Company may provide appropriate stop
orders to enforce the provisions of this paragraph.


 


(c)       
Compliance.  The Holder covenants and agrees that it will comply with the prospectus delivery requirements of
the Securities Act as applicable to it in connection with sales of Registrable Securities pursuant to the Registration Statement.


 


(d)       
Furnishing of Information.  The Holder shall furnish in writing to the Company such information regarding itself,
the Registrable Securities held by it and the intended method of disposition of the Registrable Securities held by it, as shall
be reasonably requested by the Company to effect the registration of such Registrable Securities and shall execute such documents
in connection with such registration as the Company may reasonably request.


 


(e)       
Termination of Registration Rights.  For the avoidance of doubt, it is expressly agreed and understood that
(i) in the event that there are no Registrable Securities outstanding as of a Filing Date, then the Company shall have no
obligation to file, caused to be declared effective or to keep effective any Registration Statement hereunder (including any Registration
Statement previously filed pursuant to this Agreement) and (ii) all registration rights granted to the Holders hereunder (including
the rights set forth in Section 7(a)), shall terminate in their entirety effective on the first date on which there shall
cease to be any Registrable Securities outstanding.


 


(f)       
Waivers and Amendments.  No provision of this Agreement may be waived or amended except in a written instrument
signed by the Company and the Holder or Holders (as applicable) of no less than a majority of the then outstanding Registrable
Securities.  The Company shall provide prior notice to the Holder of any proposed waiver or amendment.  No waiver of
any default with respect to any provision, condition or requirement of this Agreement shall be deemed to be a continuing waiver
in the future or a waiver of any subsequent default or a waiver of any other provision, condition or requirement hereof, nor shall
any delay or omission of either party to exercise any right hereunder in any manner impair the exercise of any such right.


 


(g)       
Governing Law; Submission to Jurisdiction.  All questions concerning the construction, validity, enforcement
and interpretation of this Agreement shall be governed by and construed and enforced in accordance with the internal laws of the
State of New York, without regard to the principles of conflicts of law thereof.  Each party agrees that all legal proceedings
concerning the interpretations, enforcement and defense of the transactions contemplated by this Agreement and any other Transaction
Documents (whether brought against a party hereto or its respective affiliates, directors, officers, shareholders, employees or
agents) shall be commenced exclusively in the state and federal courts sitting in the County of New York, in the State of New York.
Each party hereby irrevocably submits to the exclusive jurisdiction of the state and federal courts sitting in the County of New
York, in the State of New York, for the adjudication of any dispute hereunder or in connection herewith or with any transaction
contemplated hereby or discussed herein (including with respect to the enforcement of any of the Transaction Documents), and hereby
irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally subject to
the jurisdiction of any such court, that such suit, action or proceeding is improper or is an inconvenient venue for such proceeding. 
Each party hereby irrevocably waives personal service of process and consents to process being served in any such suit, action
or proceeding by mailing a copy thereof via registered or certified mail or overnight delivery (with evidence of delivery) to such
party at the address in effect for notices to it under this Agreement and agrees that such service shall constitute good and sufficient
service of process and notice thereof.  Nothing contained herein shall be deemed to limit in any way any right to serve process
in any other manner permitted by law.


 




     


     


    

 


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(h)       
Remedies.  In the event of a breach by the Company or by the Holder of any of their obligations under this Agreement,
such Holder or the Company, as the case may be, in addition to being entitled to exercise all rights granted by law and under this
Agreement, including recovery of damages, will be entitled to specific performance of its rights under this Agreement.  The
Company and the Holder agree that monetary damages would not provide adequate compensation for any losses incurred by reason of
a breach by it of any of the provisions of this Agreement and hereby further agree that, in the event of any action for specific
performance in respect of such breach, it shall waive the defense that a remedy at law would be adequate.  The remedies provided
herein are cumulative and not exclusive of any remedies provided by law.


 


(i)       
Notices.  All notices, requests, consents and other communications hereunder shall be in writing, shall be sent
by confirmed facsimile or electronic mail, or mailed by first-class registered or certified airmail, or nationally recognized overnight
express courier, postage prepaid, and shall be deemed given when so sent in the case of facsimile or electronic mail transmission,
or when so received in the case of mail or courier, and addressed as follows:


 





	if to the Company, to:	ClearSign Combustion Corporation
	 	12870 Interurban Avenue South
	 	Seattle, WA 98168
	 	Attention: Chief Executive Officer
	 	E-Mail: Steve.Pirnat@clearsign.com
	 	Facsimile: 206.673.4848
	 	 
	with a copy (which shall not constitute notice) to:	Mitchell Silberberg & Knupp LLP
	 	12 East 49th Street, 30th Floor
	 	New York, NY 10017
	 	Attn.: Melanie Figueroa, Esq.
	 	E-Mail: mxf@msk.com
	 	Facsimile: 212.509.7239
	 	 
	if to the Investor, to:	GPclirSPV LLC
	 	119 Warren Ave
	 	3rd Floor
	 	Spring Lake, NJ 07762
	 	Attention: Robert T. Hoffman Sr.
	 	E-Mail: rhoffman@princetonopp.com
	 	 
	with copies (which shall not constitute notice) to:	Bressler, Amery & Ross
	 	325 Columbia Turnpike
	 	Florham Park, NJ 07932
	 	Attention: Kim Larsen
	 	E-Mail: Klarsen@bressler.com




 


             , or to such other person, at such other
place or in such manner as one party shall designate to other party in writing.


 




     


     


    

 


Execution Copy


 


(j)       
Successors and Assigns.  This Agreement shall inure to the benefit of and be binding upon the successors and
permitted assigns of each of the parties and shall inure to the benefit of the Holder.  The Company may not assign its rights
or obligations hereunder without the prior written consent of the Holder or Holders (as applicable) of a majority of the then outstanding
Registrable Securities (other than by merger or consolidation or to an entity which acquires the Company including by way of acquiring
all or substantially all of the Company’s assets). The rights of the Holder hereunder, including the right to have the Company
register Registrable Securities pursuant to this Agreement, may be assigned by the Holder to a transferee of such Holder, but only
if (i) such Holder agrees in writing with such transferee to assign such rights and related obligations under this Agreement,
and for such transferee to assume such obligations, and a copy of such agreement is furnished to the Company, (ii) the Company
is furnished with written notice of the name and address of such transferee and the securities with respect to which such registration
rights are being transferred or assigned, (iii) such transferee agrees in writing with the Company to be bound by all of the
provisions contained herein, and (iv) such transferee is an “accredited investor,” as that term is defined in
Rule 501 of Regulation D.


 


(k)       Headings. 
The headings in this Agreement are for convenience of reference only and shall not limit or otherwise affect the meaning hereof.


 


(l)       
Severability.  If any term, provision, covenant or restriction of this Agreement is held by a court of competent
jurisdiction to be invalid, illegal, void or unenforceable, the remainder of the terms, provisions, covenants and restrictions
set forth herein shall remain in full force and effect and shall in no way be affected, impaired or invalidated, and the parties
hereto shall use their reasonable best efforts to find and employ an alternative means to achieve the same or substantially the
same result as that contemplated by such term, provision, covenant or restriction.  It is hereby stipulated and declared to
be the intention of the parties that they would have executed the remaining terms, provisions, covenants and restrictions without
including any of such that may be hereafter declared invalid, illegal, void or unenforceable.


 


(m)       
Counterparts.  This Agreement may be executed in any number of counterparts, each of which when so executed
shall be deemed to be an original and, all of which taken together shall constitute one and the same Agreement.


 


(n)       
Use of Terms.  The parties agree and acknowledge that when, in this Agreement, the Company is required to use
its reasonable best efforts to perform any covenant under this Agreement, such requirement shall not obligate the Company, in the
reasonable judgment of the disinterested members of its Board of Directors, to perform any act that will have a material adverse
effect on the Company.


 


[signature page follows]


 




     


     


    

 


Execution Copy


 


IN WITNESS WHEREOF, the parties have
executed this Registration Rights Agreement as of the date first written above.


 


	 	COMPANY:
	 	 
	 	CLEARSIGN COMBUSTION CORPORATION
	 	 
	 	By:	 
	 	Name: 	 
	 	Title:	                                       
	 	 
	 	INVESTOR:
	 	 
	 	CLIRSPV LLC
	 	 
	 	By:	 
	 	Name: 	 
	 	Title:	 








 


REGISTRATION RIGHTS AGREEMENT


 






     


     


    

 


Execution Copy


 


ANNEX A


 


PLAN OF DISTRIBUTION


 


The selling stockholder and any of its pledgees,
donees, transferees, assignees or other successors-in-interest may, from time to time, sell, transfer or otherwise dispose of any
or all of their shares of common stock or interests in shares of common stock on any stock exchange, market or trading facility
on which the shares are traded or in private transactions.  These dispositions may be at fixed prices, at prevailing market
prices at the time of sale, at prices related to the prevailing market price, at varying prices determined at the time of sale,
or at negotiated prices.  The selling stockholder may use one or more of the following methods when disposing of the shares
or interests therein:


 


		·	ordinary brokerage transactions and transactions in which
the broker-dealer solicits purchasers;



 


		·	block trades in which the broker-dealer will attempt to
sell the shares as agent but may position and resell a portion of the block as principal to facilitate the transaction;



 


		·	through brokers, dealers or underwriters that may act solely
as agents;



 


		·	purchases by a broker-dealer as principal and resale by
the broker-dealer for its account;



 


		·	an exchange distribution in accordance with the rules of
the applicable exchange;



 


		·	privately negotiated transactions;



 


		·	through the writing or settlement of options or other hedging
transactions entered into after the effective date of the registration statement of which this prospectus is a part, whether through
an options exchange or otherwise;



 


		·	broker-dealers may agree with the selling stockholder to
sell a specified number of such shares at a stipulated price per share;



 


		·	one or more underwritten offerings on a firm commitment
or best efforts basis;



 


		·	a combination of any such methods of disposition; and



 


		·	any other method permitted pursuant to applicable law.



 


The selling stockholder may also sell shares
under Rule 144 under the Securities Act of 1933, as amended, or Securities Act, if available, rather than under this prospectus.


 


Broker-dealers engaged by the selling stockholder
may arrange for other broker-dealers to participate in sales.  Broker-dealers may receive commissions or discounts from the
selling stockholder (or, if any broker-dealer acts as agent for the purchaser of shares, from the purchaser) in amounts to be negotiated. 
The selling stockholder does not expect these commissions and discounts to exceed what is customary in the types of transactions
involved.


 


The selling stockholder may from time to
time pledge or grant a security interest in some or all of the shares of common stock owned by its and, if it defaults in the performance
of its secured obligations, the pledgees or secured parties may offer and sell shares of common stock from time to time under this
prospectus, or under a supplement or amendment to this prospectus under Rule 424(b)(3) or other applicable provision
of the Securities Act amending the list of selling stockholders to include the pledgee, transferee or other successors in interest
as selling stockholders under this prospectus.


 




     


     


    

 


Execution Copy


 


Upon being notified in writing by the selling
stockholder that any material arrangement has been entered into with a broker-dealer for the sale of common stock through a block
trade, special offering, exchange distribution or secondary distribution or a purchase by a broker or dealer, we will file a supplement
to this prospectus, if required, pursuant to Rule 424(b) under the Securities Act, disclosing (i) the name of such
selling stockholder and of the participating broker-dealer(s), (ii) the number of shares involved, (iii) the price at
which such shares of common stock were sold, (iv) the commissions paid or discounts or concessions allowed to such broker-dealer(s),
where applicable, (v) that such broker-dealer(s) did not conduct any investigation to verify the information set out
or incorporated by reference in this prospectus, and (vi) other facts material to the transaction.  In addition, upon
being notified in writing by the selling stockholder that a donee or pledge intends to sell more than 500 shares of common stock,
we will file a supplement to this prospectus if then required in accordance with applicable securities law.


 


The selling stockholder also may transfer
the shares of common stock in other circumstances, in which case the transferees, pledgees or other successors in interest will
be the selling beneficial owners for purposes of this prospectus.


 


In connection with the sale of the shares
of common stock or interests in shares of common stock, the selling stockholder may enter into hedging transactions after the effective
date of the registration statement of which this prospectus is a part with broker-dealers or other financial institutions, which
may in turn engage in short sales of the common stock in the course of hedging the positions they assume.  The selling stockholder
may also sell shares of common stock short after the effective date of the registration statement of which this prospectus is a
part and deliver these securities to close out their short positions, or loan or pledge the common stock to broker-dealers that
in turn may sell these securities.  The selling stockholder may also enter into option or other transactions after the effective
date of the registration statement of which this prospectus is a part with broker-dealers or other financial institutions or the
creation of one or more derivative securities which require the delivery to such broker-dealer or other financial institution of
shares offered by this prospectus, which shares such broker-dealer or other financial institution may resell pursuant to this prospectus
(as supplemented or amended to reflect such transaction).


 


The selling stockholder and any broker-dealers
or agents that are involved in selling the shares may be deemed to be “underwriters” within the meaning of the Securities
Act in connection with such sales.  In such event, any commissions received by such broker-dealers or agents and any profit
on the resale of the shares purchased by them may be deemed to be underwriting commissions or discounts under the Securities Act. 
The maximum commission or discount to be received by any member of the Financial Industry Regulatory Authority (FINRA) or independent
broker-dealer will not be greater than 8% of the initial gross proceeds from the sale of any security being sold.


 


We have advised the selling stockholder
that it is required to comply with Regulation M promulgated under the Securities Exchange Act during such time as it may be engaged
in a distribution of the shares.  The foregoing may affect the marketability of the common stock.


 


The aggregate proceeds to the selling stockholder
from the sale of the common stock offered by it will be the purchase price of the common stock less discounts or commissions, if
any.  The selling stockholder reserves the right to accept and, together with its agents from time to time, to reject, in
whole or in part, any proposed purchase of common stock to be made directly or through agents.  We will not receive any of
the proceeds from this offering.


 


We are required to pay all fees and expenses
incident to the registration of the shares.  We have agreed to indemnify the selling stockholder against certain losses, claims,
damages and liabilities, including liabilities under the Securities Act or otherwise.


 


We have agreed with the selling stockholder
to keep the registration statement of which this prospectus constitutes a part effective until the earlier of (a) such time
as all of the shares covered by this prospectus have been disposed of pursuant to and in accordance with the registration statement,
and (b) the date on which the shares of common stock covered by this prospectus may be sold by non-affiliates without any
volume or manner of sale restrictions or current public information pursuant to Rule 144 of the Securities Act.


 




     


     


    

 


Execution Copy


 


APPENDIX II


 


SELLING STOCKHOLDER QUESTIONNAIRE


 




     


     


    

 


Execution Copy


 


SELLING STOCKHOLDER NOTICE AND QUESTIONNAIRE


 


	 	 
	 	Name of Selling Stockholder (please print)


 


CLEARSIGN COMBUSTION CORPORATION


QUESTIONNAIRE FOR SELLING STOCKHOLDERS


 


IMPORTANT:  IMMEDIATE ATTENTION
REQUIRED


 


This Questionnaire is being furnished to
all persons or entities (the “Purchasers”) who purchased shares of Common Stock (“Common Stock”) of ClearSign
Combustion Corporation (the “Company”) pursuant to the Stock Purchase Agreement by and among the Company and the Purchaser
(the “Purchase Agreement”).  This Questionnaire relates to certain information required to be disclosed in the
Registration Statement on Form S-3 (the “Registration Statement”) to be prepared by the Company for filing with
the United States Securities and Exchange Commission (the “SEC”) pursuant to the Registration Rights Agreement entered
into by and among the Company and the Purchaser (the “Registration Rights Agreement”) in connection with the Purchase
Agreement.  The Company must receive a completed Questionnaire from each Purchaser in order to include such Purchaser’s
shares of Common Stock in the Registration Statement.


 


The furnishing of accurate and complete
responses to the questions posed in this Questionnaire is an extremely important part of the registration process.  The inclusion
of inaccurate or incomplete disclosures in the Registration Statement can result in potential liabilities, both civil and criminal,
to the Company and to the individuals who furnish the information.  Accordingly, Purchaser is advised to consult its own securities
law counsel regarding the consequences of being named or not being named as a selling securityholder in the Registration Statement
and related prospectus.


 


PLEASE GIVE A RESPONSE TO EVERY QUESTION,
indicating “None” or “Not Applicable” where appropriate.  Please complete, sign, and return
one copy of this Questionnaire by facsimile, email or overnight courier as soon as possible.


 


Unless stated otherwise, answers should
be given as of the date you complete this Questionnaire.  However, it is your responsibility to inform us of any changes that
may occur to your situation.  If there is any situation about which you have any doubt, or if you are uncertain as to the
meaning of any terms used in this Questionnaire, please contact [                      ]


 


PART I - STOCK OWNERSHIP


 


Item 1.  Beneficial Ownership.


 


a.  Deemed Beneficial Ownership. 
Please state the amount of securities of the Company you own on the date you complete this Questionnaire.  (If none, please
so state in each case.)


 






     


     


    

 


Execution Copy


 


	 	 	Number of Shares of
	Amount Beneficially Owned(1)	 	Common Stock Owned
	 	 	 
	Please state the number of shares owned by you or by family members, trusts and other organizations with which you have a relationship, and any other shares of which you may be deemed to be the “beneficial owner”(1):	 	 
	 	 	 
	Total Shares:	 	 
	 	 	 
	Of such shares:	 	 
	 	 	 
	Shares as to which you have sole voting power:	 	 
	 	 	 
	Shares as to which you have shared voting power:	 	 
	 	 	 
	Shares as to which you have sole investment power:	 	 
	 	 	 
	Shares as to which you have shared investment power:	 	 
	 	 	 
	Shares which you will have a right to acquire before 60 days after the date you complete this questionnaire through the exercise of options, warrants or otherwise:	 	 


 


Do you have any present plans to exercise
options or otherwise acquire, dispose of or to transfer shares of Common Stock of the Company between the date you complete this
Questionnaire and the date which is 60 days after the date in which the Registration Statement is filed?


 


Answer:


 


If so, please describe.


 


b.              Pledged Securities.  If any of such securities have been pledged or otherwise deposited as collateral or are the subject
matter of any voting trust or other similar agreement or of any contract providing for the sale or other disposition of such securities,
please give the details thereof.


 


Answer:


 


c.              Disclaimer of Beneficial Ownership.  Do you wish to disclaim beneficial ownership(1) of any of the shares reported
in response to Item 1(a)?


 


Answer:


 


If the answer is “Yes”, please
furnish the following information with respect to the person or persons who should be shown as the beneficial owner(s)(1) of
the shares in question.


 


	Name and Address of	 	Relationship of	 	Number of Shares
	Actual Beneficial Owner	 	Such Person To You	 	Beneficially Owned
	 	 	 	 	 
	 	 	 	 	 
	 	 	 	 	 


 


d.              Shared Voting or Investment Power over Securities.  Will any person be deemed to have beneficial ownership over any
of the Securities purchased by you pursuant to the Purchase Agreement?


 


Answer:


 


If the answer is “Yes”, please
furnish the following information with respect to the person or persons who should be shown as the beneficial owner(s)(1) of
the Securities in question.


 


	Name and Address of	 	Relationship of	 	Number of Shares
	Beneficial Owner	 	Such Person To You	 	Beneficially Owned
	 	 	 	 	 
	 	 	 	 	 
	 	 	 	 	 


 












     


     


    

 


Execution Copy


 


Item 2.  Major Shareholders. 
Please state below the names of persons or groups known by you to own beneficially(1) more than 5% of the Company’s
Common Stock.


 


Answer:


 


Item 3.  Change of Control. 
Do you know of any contractual arrangements, including any pledge of securities of the Company, the operation of which may at a
subsequent date result in a change of control of the Company?


 


Answer:


 


Item 4.  Relationship with
the Company.  Please state the nature of any position, office or other material relationship you have, or have had within
the past three years, with the Company or its affiliates.


 


	 	 	Nature of
	Name	 	Relationship
	 	 	 
	 	 	 
	 	 	 


 


Item 5.  Broker-Dealer Status. 
Is the Purchaser a broker-dealer registered pursuant to Section 15 of the Securities Exchange Act of 1934, as amended (the
“Exchange Act”)?


 


o
Yes.


 


o
No.


 


If so, please answer the remaining questions
under this Item 5.


 


Note that the Company will be required
to identify any registered broker-dealer as an underwriter in the Registration Statement and related prospectus.


 


a.              If the Purchaser is a registered broker-dealer, please indicate whether the Purchaser purchased its Common Stock for investment
or acquired them as transaction-based compensation for investment banking or similar services.


 


Answer:


 


Note that if the Purchaser is a registered
broker-dealer and received its Common Stock other than as transaction-based compensation, the Company is required to identify the
Purchaser as an underwriter in the Registration Statement and related prospectus.


 


b.              Is the Purchaser an affiliate of a registered broker-dealer? For purposes of this Question, an “affiliate” of a specified
person or entity means a person or entity that directly, or indirectly through one or more intermediaries, controls or is controlled
by, or is under common control with, the person or entity specified.


 


o
Yes.


 


o
No.


 


If so, please answer questions (i)-(iii) below
under this Item 5(b).


 


i.              Please describe the affiliation between the Purchaser and any registered broker-dealers:


 




     


     


    

 


Execution Copy


 


ii.               If the Common Stock was received by the Purchaser other than in the ordinary course of business, please describe the circumstances:


 


iii.              If the Purchaser, at the time of its receipt of Common Stock, has had any agreements or understandings, directly or indirectly,
with any person to distribute the Common Stock, please describe such agreements or understandings:


 


Note that if the Purchaser is an affiliate
of a broker-dealer and did not receive its Common Stock in the ordinary course of business or at the time of receipt
had any agreements or understandings, directly or indirectly, to distribute the securities, the Company must identify the Purchaser
as an underwriter in the Registration Statement and related prospectus.


 


Item 6.  Nature of Beneficial
Holding.  The purpose of this question is to identify the ultimate natural person(s) or publicly held entity that
exercise(s) sole or shared voting or dispositive power over the Registrable Securities (as defined in the Registration Rights
Agreement).


 


a.           Is the Purchaser a natural person?


 


o
Yes.


 


o
No.


 


b.           Is the Purchaser required to file, or is it a wholly owned subsidiary of a company that is required to file, periodic and other
reports (for example, Form 10-K, 10-Q, 8-K) with the SEC pursuant to Section 13(a) or 15(d) of the Exchange
Act?


 


o
Yes.


 


o
No.


 


c.           Is the Purchaser an investment company, or a subsidiary of an investment company, registered under the Investment Company Act of
1940, as amended?


 


o
Yes.


 


o
No.


 


If a subsidiary, please identify the publicly
held parent entity:


 


d.           If you answered “no” to questions (a), (b) and (c) above, please identify the controlling person(s) of
the Purchaser (the “Controlling Entity”). If the Controlling Entity is not a natural person or a publicly held entity,
please identify each controlling person(s) of such Controlling Entity. This process should be repeated until you reach natural
persons or a publicly held entity that exercises sole or shared voting or dispositive power over the Registrable Securities:


 


***PLEASE NOTE THAT THE SEC REQUIRES
THAT THESE NATURAL PERSONS BE NAMED IN THE PROSPECTUS***


 


PART II - CERTAIN TRANSACTIONS


 


Item 7.  Transactions with
the Company.  If you, any of your associates(2), or any member of your immediate family(3) had or will have any direct
or indirect material interest in any transactions(4) or series of transactions to which the Company or any of its subsidiaries
was a party at any time since January 1, 2015, or in any currently proposed transactions or series of transactions in which
the Company or any of its subsidiaries will be a party, in which the amount involved exceeds $120,000, please specify (a) the
names of the parties to the transaction(s) and their relationship to you, (b) the nature of the interest in the transaction,
(c) the amount involved in the transaction, and (d) the amount of the interest in the transaction.  If the answer
is “none”, please so state.


 




     


     


    

 


Execution Copy


 


Answer:


  


Item 8.  Third Party Payments. 
Please describe any compensation paid to you by a third party pursuant to any arrangement between the Company and any such third
party.


 


Answer:


 


PART III — PLAN OF DISTRIBUTION


 


The selling stockholder and any of its pledgees,
donees, transferees, assignees or other successors-in-interest may, from time to time, sell, transfer or otherwise dispose of any
or all of their shares of common stock or interests in shares of common stock on any stock exchange, market or trading facility
on which the shares are traded or in private transactions.  These dispositions may be at fixed prices, at prevailing market
prices at the time of sale, at prices related to the prevailing market price, at varying prices determined at the time of sale,
or at negotiated prices.  The selling stockholder may use one or more of the following methods when disposing of the shares
or interests therein:


 


		·	ordinary brokerage transactions and transactions in which
the broker-dealer solicits purchasers;



 


		·	block trades in which the broker-dealer will attempt to
sell the shares as agent but may position and resell a portion of the block as principal to facilitate the transaction;



 


		·	through brokers, dealers or underwriters that may act solely
as agents;



 


		·	purchases by a broker-dealer as principal and resale by
the broker-dealer for its account;



 


		·	an exchange distribution in accordance with the rules of
the applicable exchange;



 


		·	privately negotiated transactions;



 


		·	through the writing or settlement of options or other hedging
transactions entered into after the effective date of the registration statement of which this prospectus is a part, whether through
an options exchange or otherwise;



 


		·	broker-dealers may agree with the selling stockholder to
sell a specified number of such shares at a stipulated price per share;



 


		·	one or more underwritten offerings on a firm commitment
or best efforts basis;



 


		·	a combination of any such methods of disposition; and



 


		·	any other method permitted pursuant to applicable law.



 




     


     


    

 


Execution Copy


 


The selling stockholder may also sell shares
under Rule 144 under the Securities Act of 1933, as amended, or Securities Act, if available, rather than under this prospectus.


 


Broker-dealers engaged by the selling stockholder
may arrange for other broker-dealers to participate in sales.  Broker-dealers may receive commissions or discounts from the
selling stockholder (or, if any broker-dealer acts as agent for the purchaser of shares, from the purchaser) in amounts to be negotiated. 
The selling stockholder does not expect these commissions and discounts to exceed what is customary in the types of transactions
involved.


 


The selling stockholder may from time to
time pledge or grant a security interest in some or all of the shares of common stock owned by its and, if it defaults in the performance
of its secured obligations, the pledgees or secured parties may offer and sell shares of common stock from time to time under this
prospectus, or under a supplement or amendment to this prospectus under Rule 424(b)(3) or other applicable provision of the Securities
Act amending the list of selling stockholders to include the pledgee, transferee or other successors in interest as selling stockholders
under this prospectus.


 


Upon being notified in writing by the selling
stockholder that any material arrangement has been entered into with a broker-dealer for the sale of common stock through a block
trade, special offering, exchange distribution or secondary distribution or a purchase by a broker or dealer, we will file a supplement
to this prospectus, if required, pursuant to Rule 424(b) under the Securities Act, disclosing (i) the name of such selling stockholder
and of the participating broker-dealer(s), (ii) the number of shares involved, (iii) the price at which such shares of common stock
were sold, (iv) the commissions paid or discounts or concessions allowed to such broker-dealer(s), where applicable, (v) that such
broker-dealer(s) did not conduct any investigation to verify the information set out or incorporated by reference in this prospectus,
and (vi) other facts material to the transaction.  In addition, upon being notified in writing by the selling stockholder
that a donee or pledge intends to sell more than 500 shares of common stock, we will file a supplement to this prospectus if then
required in accordance with applicable securities law.


 


The selling stockholder also may transfer
the shares of common stock in other circumstances, in which case the transferees, pledgees or other successors in interest will
be the selling beneficial owners for purposes of this prospectus.


 


In connection with the sale of the shares
of common stock or interests in shares of common stock, the selling stockholder may enter into hedging transactions after the effective
date of the registration statement of which this prospectus is a part with broker-dealers or other financial institutions, which
may in turn engage in short sales of the common stock in the course of hedging the positions they assume.  The selling stockholder
may also sell shares of common stock short after the effective date of the registration statement of which this prospectus is a
part and deliver these securities to close out their short positions, or loan or pledge the common stock to broker-dealers that
in turn may sell these securities.  The selling stockholder may also enter into option or other transactions after the effective
date of the registration statement of which this prospectus is a part with broker-dealers or other financial institutions or the
creation of one or more derivative securities which require the delivery to such broker-dealer or other financial institution of
shares offered by this prospectus, which shares such broker-dealer or other financial institution may resell pursuant to this prospectus
(as supplemented or amended to reflect such transaction).


 


The selling stockholder and any broker-dealers
or agents that are involved in selling the shares may be deemed to be “underwriters” within the meaning of the Securities
Act in connection with such sales.  In such event, any commissions received by such broker-dealers or agents and any profit
on the resale of the shares purchased by them may be deemed to be underwriting commissions or discounts under the Securities Act. 
The maximum commission or discount to be received by any member of the Financial Industry Regulatory Authority (FINRA) or independent
broker-dealer will not be greater than 8% of the initial gross proceeds from the sale of any security being sold.


 


We have advised the selling stockholder
that it is required to comply with Regulation M promulgated under the Securities Exchange Act during such time as it may be engaged
in a distribution of the shares.  The foregoing may affect the marketability of the common stock.


 




     


     


    

 


Execution Copy


 


The aggregate proceeds to the selling stockholder
from the sale of the common stock offered by it will be the purchase price of the common stock less discounts or commissions, if
any.  The selling stockholder reserves the right to accept and, together with its agents from time to time, to reject, in
whole or in part, any proposed purchase of common stock to be made directly or through agents.  We will not receive any of
the proceeds from this offering.


 


We are required to pay all fees and expenses
incident to the registration of the shares.  We have agreed to indemnify the selling stockholder against certain losses, claims,
damages and liabilities, including liabilities under the Securities Act or otherwise.


 


We have agreed with the selling stockholder
to keep the registration statement of which this prospectus constitutes a part effective until the earlier of (a) such time as
all of the shares covered by this prospectus have been disposed of pursuant to and in accordance with the registration statement,
and (b) the date on which the shares of common stock covered by this prospectus may be sold by non-affiliates without any volume
or manner of sale restrictions or current public information pursuant to Rule 144 of the Securities Act.


 


*         *         *


 


The undersigned has reviewed the Plan of
Distribution set forth above and does not have a present intention of effecting a sale in a manner not described therein.


 


	 	o	Agree	o	Disagree	 
	 	 	(If left blank, response will be deemed to be “Agree”.)	 


 


The undersigned hereby represents that the
undersigned understands, pursuant to Securities Act Sections Compliance and Disclosure Interpretations Section 239.10, a copy of
which is attached hereto as Exhibit 1, that the undersigned may not make any short sale of the Common Stock prior to the effectiveness
of the Registration Statement, and further covenants to the Company that the undersigned will not engage in any short sales of
such stock to be registered under the Registration Statement prior to its effectiveness.


 


SIGNATURE


 


The undersigned understands that the Company
anticipates filing the Registration Statement within the time frame set forth in the Registration Rights Agreement.  If at
any time any of the information set forth in my responses to this Questionnaire has materially changed due to passage of time (other
than due to the receipt of the Common Stock set forth opposite the undersigned’s name in the Schedule of Purchasers in the
Purchase Agreement), or any development occurs which requires a change in any of my answers, or has for any other reason become
incorrect, the undersigned agrees to furnish as soon as practicable to the individual to whom a copy of this Questionnaire is to
be sent, as indicated and at the address shown on the first page hereof, any necessary or appropriate correcting information. 
Otherwise, the Company is to understand that the above information continues to be, to the best of my knowledge, information and
belief, complete and correct.


 


Upon any sale of Common Stock pursuant to
the Registration Statement, the undersigned hereby agrees to deliver to the Company and the Company’s transfer agent the
Certificate of Subsequent Sale set forth in Exhibit I hereto.


 


The undersigned understands that the information
that the undersigned is furnishing to the Company herein will be used by the Company in the preparation of the Registration Statement.


 


	 	Name of Purchaser:	 
	 	 
	 	 
	Date:                                   , 201_	Signature:	 
	 	 
	 	 
	 	Print Name:	 
	 	 
	 	 
	 	Title (if applicable):	           
	 	 
	 	 
	 	Address:




 






     


     


    

 


Execution Copy


 


FOOTNOTES


 


		1.	Beneficial Ownership.  You are the beneficial
owner of a security, as defined in Rule 13d-3 under the Securities Exchange Act of 1934 (the “Exchange Act”), if you,
directly or indirectly, through any contract, arrangement, understanding, relationship or otherwise have or share: (1) voting
power, which includes the power to vote, or to direct the voting of, such security, and/or (2) investment power, which includes
the power to dispose, or to direct the disposition of, such security.  You are also the beneficial owner of a security if
you, directly or indirectly, create or use a trust, proxy, power of attorney, pooling arrangement or any other contract, arrangement
or device with the purpose or effect of divesting yourself of beneficial ownership of a security or preventing the vesting of
such beneficial ownership.



 


You are deemed to be the beneficial owner of a security
if you have the right to acquire beneficial ownership of such security at any time within 60 days including, but not limited
to, any right to acquire such security (a) through the exercise of any option, warrant or right, (b) through the conversion of
a security, or (c) pursuant to the automatic termination of, or the power to revoke a trust, discretionary account, or similar
arrangement.


 


Ordinarily, shares held in the name of your spouse
or minor child should be considered as beneficially owned by you absent special circumstances to indicate that you do not have,
as a practical matter, voting power or investment power over such shares.  Similarly, absent countervailing facts, securities
held in the name of relatives who share your home are to be reported as being beneficially owned by you.  In addition, securities
held for your benefit in the name of others, such as nominees, trustees and other fiduciaries, securities held by a partnership
of which you are a partner, and securities held by a corporation controlled by you should be regarded as beneficially owned by
you.


 


This definition of beneficial ownership is very broad;
therefore, even though you may not actually have or share voting or investment power with respect to securities owned by persons
in your family or living in your home, you should include such shares in your beneficial ownership disclosure and may then disclaim
beneficial ownership of such securities.


 


		2.	Associate.  The term “associate”,
as defined in Rule 14a-1 under the Exchange Act, means (a) any corporation or organization (other than the Company or any of its
majority owned subsidiaries) of which you are an officer or partner or are, directly or indirectly, the beneficial owner of 10%
or more of any class of equity securities, (b) any trust or other estate in which you have a substantial beneficial interest or
as to which you serve as trustee or in a similar capacity, and (c) your spouse, or any relative of yours or relative of your spouse
living in your home or who is a director or officer of the Company or of any subsidiary.  The term “relative of yours”
as used in this Questionnaire refers to any relative or spouse of yours, or any relative of such spouse, who has the same home
as you or who is a director or officer of any subsidiary of the Company.



 


Please identify your associate referred to in your
answer and indicate your relationship.


 


		3.	Immediate Family.  The members of your “immediate
family” are deemed to include the following:  your spouse; your parents; your children; your siblings; your mother-in-law
or father-in-law; your sons- and daughters-in-law; and your brothers- and sisters-in-law.



 


		4.	Transactions.  The term “transaction”
is to be understood in its broadest sense, and includes the direct or indirect receipt of anything of value.  Please note
that indirect as well as direct material interests in transactions are to be disclosed.  Transactions in which you would
have a direct interest would include your purchasing or leasing anything (stock in a business acquired by the Company, office
space, plants, Company apartments, computers, raw materials, finished goods, etc.) from or selling or leasing anything to, or
borrowing or lending cash or other property from or to, the Company, or any subsidiary.]



 




     


     


    

 


Execution Copy


 


Exhibit I


 


CERTIFICATE OF SUBSEQUENT SALE


 


[Transfer Agent]


 


		RE:	Sale of Shares of Common Stock of ClearSign Combustion
Corporation (the “Company”) pursuant to the Company’s Prospectus dated                              ,
(the “Prospectus”)



 


Dear Sir/Madam:


 


The undersigned hereby certifies, in connection
with the sale of shares of Common Stock of the Company included in the table of Selling Stockholders in the Prospectus, that the
undersigned has sold the shares pursuant to the Prospectus and in a manner described under the caption “Plan of Distribution”
in the Prospectus and that such sale complies with all securities laws applicable to the undersigned, including, without limitation,
the Prospectus delivery requirements of the Securities Act of 1933, as amended.


 


	Selling Stockholder (the beneficial owner): 	 


 


	Record Holder (e.g., if held in name of nominee): 	 


 


	Book Entry Position or Restricted Stock Certificate No.(s): 	 


 


	Number of Shares Sold:	 


 


	Date of Sale:	   


 


In the event that you receive a stock certificate(s)
or evidence of a book entry position representing more shares of Common Stock than have been sold by the undersigned, then you
should return to the undersigned a newly issued certificate or book entry position for such excess shares in the name of the Record
Holder and BEARING A RESTRICTIVE LEGEND.  Further, you should place a stop transfer on your records with regard to
such certificate.  Notwithstanding the foregoing, in the event that the undersigned executes and delivers to you and to the
Company the certification set forth on Annex I, upon instructions from the Company, you should return to the undersigned a newly
issued certificate or book entry position for such excess shares of Common Stock in the name of the Record Holder without any restrictive
legend.  In addition, no subsequent certification will be required to be delivered to you by the undersigned provided that
the representations and warranties set forth on Annex I have been delivered to you and continue to be accurate.


 


	 	 	Very truly yours,
	 	 	 
	Dated: 	 	 	By:	 
	 	 	 
	 	 	Print Name: 	 
	 	 	 
	 	 	Title:	 




 


		cc:	ClearSign Combustion Corporation



[Address]


Attention:


 




     


     


    

 


Execution Copy


 


Annex I


 


In connection with any excess shares to
be returned to the Selling Stockholder upon a sale of shares of Common Stock of ClearSign Combustion Corporation (the “Company”)
included in the table of Selling Stockholders in the Prospectus, the undersigned hereby certifies to the Company and [Transfer
Agent], that:


 


1.            In connection with the sale by the undersigned stockholder of any of the shares of Common Stock pursuant to the Prospectus, the
undersigned stockholder will deliver a copy of the Prospectus included in the Registration Statement to the purchaser directly
or through the undersigned stockholder’s broker-dealer in compliance with the requirements of the Securities Act of 1933
and the Securities Exchange Act of 1934.


 


2.            Any such sale will be made only in the manner described under “Plan of Distribution” in the Prospectus.


 


3.            The undersigned stockholder will only sell the shares of Common Stock while the Registration Statement is effective, unless another
exemption from registration is available.


 


4.            The Company and its attorneys may rely on this letter to the same extent as if it were addressed to them.


 


5.            The undersigned stockholder agrees to notify you immediately of any development or occurrence which to his, her or its knowledge
would render any of the foregoing representations and agreements inaccurate.


 


All terms not defined herein are as defined
in the Stock Purchase Agreement entered into in _______ 2018 between the Company and the Purchaser.


 


	 	 	Very truly yours,
	 	 	 
	Dated: 	 	 	By:	 
	 	 	 
	 	 	Print Name: 	 
	 	 	 
	 	 	Title:	 


 


 ]


  










    	 



     


    

 


Execution Copy


 


APPENDIX IV


 


1.          Purchase
Rights with Respect to Outstanding $4.00 Warrants. As it relates solely to, and in conjunction with, the exercise of the warrants
issued by the Company on January 25, 2017, (the “Warrants”) and the issuance of the Common Stock subject to
the Warrants (the “Warrant Shares”) for a period beginning on the Closing and ending seven days following the
Expiration Date under the Warrant Agreement, as defined below, as the Expiration Date may be extended (the “Purchase Period”),
the Purchaser will have the right (the "Purchase Right"), as Warrants are exercised and Warrant Shares
are issued, to purchase from the Company a number of shares of Common Stock sufficient to maintain a percentage ownership of 19.99%
of the Company’s outstanding Common Stock, up to a total of 478,854 shares of Common Stock, on the same terms and conditions
as if such right had been granted pursuant to the Warrant Agreement between the Company and VStock Transfer, LLC dated December
7, 2016 (the "Warrant Agreement"). The price for the purchase of such Common Stock shall be the Warrant
Price. Such shares of Common Stock shall be issued by the Company directly to the Purchaser upon payment to the Company, by certified
or bank check or wire transfer of immediately available funds, of the Warrant Price per share of Common Stock. The number of shares
of Common Stock for which the Purchase Right may be exercised and the Warrant Price are both subject to adjustment as provided
in the Warrant Agreement as if the Purchase Right were granted as Warrants pursuant to the terms of such Warrant Agreement. The
Purchaser may exercise the Purchase Right in full or in part at any time during the Purchase Period by (i) providing notice to
the Company of the number of shares of Common Stock to be purchased, and (ii) paying the Warrant Price for each such share of Common
Stock. In no event, however, may the Purchase Right be exercised to the extent it would cause Purchaser or any of its Affiliates
to beneficially own 20% or more of the Company’s then outstanding Common Stock or hold shares with 20% or more of the voting
power of the Company. Until the expiration of the Purchase Period, the Purchase Right may subsequently be exercised for any shares
of Common Stock for which the Purchase Right had not previously been exercised. The Company shall represent and warrant to the
Purchaser that shares purchased by the Purchaser pursuant to the Purchase Right shall be, upon issuance thereof to the Purchaser
and after payment therefor, duly authorized, validly issued, fully paid and non-assessable. As soon as possible after the termination
date of the Exercise Period, the Company shall inform Purchaser of the number of shares of Common Stock issued pursuant to the
exercise of rights under the Warrant Agreement, but in in no event later than four days after the expiration of the Exercise Period.
Capitalized terms in this Section not otherwise defined are used as defined in the Warrant Agreement.


 


2.          Issuance
of Additional Equity Securities.


 


a.           Participation
Right. The Company hereby grants to the Purchaser the right (the “Participation Right”) to purchase, on
terms and conditions no different from those offered to other purchasers, its Purchaser Pro Rata Portion of any new Equity Securities
(other than any Excluded Securities) (the "New Securities") that the Company
may from time to time propose to issue or sell for the purpose of raising capital. In no event, however, may the Participation
Right be exercised to the extent it would cause Purchaser to own 20% or more of the Company’s then outstanding Common Stock
or hold shares with 20% or more of the voting power of the Company. This right shall expire on December 31, 2023.


 


b.           Additional
Issuance Notices. The Company shall give the Purchaser written notice (an "Issuance Notice")
of any proposed issuance or sale described in subsection (a) above within five Business Days following any meeting of the Board
at which any such issuance or sale is approved. If the proposed issuance will be exempt from registration pursuant to Section 4(a)(2)
of the Securities Act, the Issuance Notice, if applicable, shall be accompanied by a written offer from any prospective purchaser
seeking to purchase New Securities and shall set forth the material terms and conditions of the proposed issuance, including:


 


i.          the
number and description of the New Securities proposed to be issued and the percentage of the Company's outstanding Equity Securities
such issuance would represent;


 


ii.         the
proposed issuance date, which shall be at least 20 days from the date of the Issuance Notice; and


 


iii.         the
proposed purchase price per share.


 




    	 



     


    

 


Execution Copy


 


c.           Exercise
of Participation Rights. The Purchaser shall for a period of 15 days following the receipt of an Issuance Notice (the "Exercise
Period") have the right to elect irrevocably to exercise its Participation Right to purchase its Purchaser Pro Rata Portion
of the New Securities at the purchase price set forth in the Issuance Notice by delivering a written notice to the Company. The
closing of any purchase by the Purchaser shall be consummated concurrently with the consummation of the issuance or sale described
in the Issuance Notice.


 


d.           Sales
to the Prospective Buyer. If the Purchaser fails to purchase its Purchaser Pro Rata Portion of the New Securities within the
time period described in subsection (c), the Company shall be free to complete the proposed issuance or sale of New Securities
described in the Issuance Notice with respect to which the Purchaser failed to exercise the option set forth in this Section 2
on terms no less favorable to the Company than those set forth in the Issuance Notice (except that the amount of New Securities
to be issued or sold by the Company may be reduced); provided, that (x) such issuance or sale is closed within 60 Business
Days after the expiration of the Exercise Period (subject to the extension of such 60 Business Day period for a reasonable time
not to exceed 60 Business Days to the extent reasonably necessary to obtain any approval from NASDAQ or any approval required by
state or federal securities laws) and (y) for the avoidance of doubt, the price at which the New Securities are sold is at least
equal to or higher than the purchase price described in the Issuance Notice. In the event the Company has not sold such New Securities
within such time period, the Company shall not thereafter issue or sell any New Securities without first again offering such securities
to the Purchaser in accordance with the procedures set forth in this Section 2.


 


e.           Closing
of the Issuance. Upon the issuance of any New Securities in accordance with this Section 2, the Company shall deliver to the
Purchaser certificates (if any) evidencing the New Securities purchased by the Purchaser pursuant to the Participation Right, which
New Securities shall be issued free and clear of any liens (other than those arising hereunder and those attributable to the actions
of the purchasers thereof), and the Company shall so represent and warrant to the Purchaser, and further represent and warrant
to the Purchaser that such New Securities shall be, upon issuance thereof to the Purchaser and after payment therefor, duly authorized,
validly issued, fully paid and non-assessable. The Purchaser shall deliver to the Company the purchase price for the New Securities
purchased by it by certified or bank check or wire transfer of immediately available funds. Each party to the purchase and sale
of New Securities shall take all such other actions as may be reasonably necessary to consummate the purchase and sale including,
without limitation, entering into such additional agreements as may be necessary or appropriate.


 


f.            Definitions
for this Exhibit. The following terms shall apply to this Section 2:


 


“Business Day” means
any day other than Saturday, Sunday or other day on which commercial banks in The City of New York are authorized or required by
law to remain closed.


 


“Equity Securities” means
only the Company’s Common Stock and warrants to purchase the Company’s Common Stock.


 


"Excluded Securities" means
Equity Securities issued in connection with: (i) shares of Common Stock issued pursuant to the exercise of currently outstanding
warrants or options issued pursuant to equity incentive plans or other compensation arrangements; (ii) securities issued in debt
financing transactions with any financial institution or company; (iii) securities issued in transactions with strategic partners
such as customers, suppliers or distributors; (iv) securities issued in rights or other securities offerings made to all stockholders;
and (v) securities issued pursuant to stockholder-approved transactions including any transaction resulting in a change of control.
Transactions with strategic partners shall include, but shall not be limited to, (A) the consolidation or merger by the Company
(or its subsidiaries or affiliates) with or into (whether or not the Company is the surviving corporation) another entity; (B)
the sale, assignment, transfer, conveyance or disposition of all or substantially all of the properties or assets of the Company
or any of its significant subsidiaries; (C) allowing one or more entities to make, or allowing the Company to be subject to or
have its Common Stock be subject to, a purchaser, tender or exchange offer; (D) the consummation of a stock or share purchase agreement
with a strategic partner; or (E) the consummation with a strategic partner of any other business combination (including, without
limitation, a reorganization, recapitalization, spin-off or scheme of arrangement).


 


"Purchaser Pro Rata Portion" means
the number of New Securities sufficient to permit Purchaser to maintain ownership of 19.99% of the Company’s outstanding
Common Stock following the issuance of the New Securities.


 




    	 



     


    

 


Execution Copy


 


SCHEDULE OF EXCEPTIONS


July 11, 2018


 


This Schedule of Exceptions is being furnished
by ClearSign Combustion Corporation, a Washington corporation, (the “Company”), to the Purchaser party to that
certain Stock Purchase Agreement of even date herewith by and among the Company and such Purchaser (the “Agreement”)
in connection with the execution and delivery of the Agreement, pursuant to Section 4 of the Agreement.  Unless the context
otherwise requires, all capitalized terms used in this Schedule of Exceptions shall have the respective meanings ascribed to such
terms in the Agreement.


 


This Schedule of Exceptions and the information,
descriptions and disclosures included herein is intended to set forth exceptions to the representations and warranties of the Company
contained in the Agreement.  The contents of all agreements and other documents referred to in a particular section of this
Schedule of Exceptions are incorporated by reference into such particular section as though fully set forth in such section.


 




    	 



     


    

 


Execution Copy


 


SCHEDULE 1


 


Form of Affiliate Legend


 


“THE SHARES REPRESENTED BY THIS CERTIFICATE ARE HELD BY
AN AFFILIATE OF THE ISSUER AS DEFINED IN RULE 144 PROMULGATED UNDER THE SECURITIES ACT OF 1933 AND MAY ONLY BE SOLD OR OTHERWISE
TRANSFERRED IN COMPLIANCE WITH THE REQUIREMENTS OF RULE 144 OR PURSUANT TO A REGISTRATION STATEMENT UNDER SAID ACT OR AN EXEMPTION
FROM SUCH REGISTRATION.”


 




    	 



     


    

 


Execution Copy


 


SCHEDULE 4.6


 


1.          The
Company has an agreement with Three Part Advisors, LLC pursuant to which it issues to this entity, from the Company’s 2013
Consultant Stock Plan, shares of Common Stock in partial payment for services rendered.


 


2.          The
Company intends to issue options to purchase shares of its Common Stock to certain employees and directors. The options will be
issued from the Company’s 2011 Equity Incentive Plan (the “2011 Plan”).


 


3.          Each
quarter the shares of Common Stock included in the 2011 Plan are increased as follows:


 


The maximum aggregate number of Shares that may be
granted under the 2011 Plan will be increased effective the first day of each of the Company’s fiscal quarters, beginning
with the fiscal quarter commencing October 1, 2011, (the “Adjustment Date”) by an amount equal to the lesser of:


 


(i) 10% of the difference between the number of shares
of Common Stock outstanding on the applicable Adjustment Date and the number of shares of Common Stock outstanding at the beginning
of the fiscal quarter immediately preceding the Adjustment Date; or


 


(ii) such lesser number of Shares as may be determined
by the Board.


 


The shares included in the 2013 Consultant
Stock Plan are increased in the same manner, at a rate of 1% of the difference between the number of shares of Common Stock outstanding
on the applicable Adjustment Date and the number of shares of Common Stock outstanding at the beginning of the fiscal quarter immediately
preceding the Adjustment date.


 


4.          Brean
Capital, LLC was issued a warrant for the purchase of 20,313 shares of Common Stock at an exercise price of $10.00 per share. The
warrant will expire on March 5, 2019. Brean Capital LLC will continue to have demand registration rights until March 5, 2019.


 


5.          The
Company intends on filing a registration statement on Form S-8 to cover additional shares of Common Stock included in the 2011
Equity Incentive Plan.


 


6.          On
April 1, 2018, in accordance with the quarterly increases permitted under the 2011 Plan as described at paragraph 3 above, the
number of shares of Common Stock reserved for issuance was increased by 575,250 shares.


 


7.          On
April 1, 2018, in accordance with the quarterly increases permitted under the 2013 Consultant Stock Plan as described in paragraph
3 above, the number of shares of Common Stock reserved for issuance was increased by 57,525 shares.


 


8.          On
April 12, 2018, the Compensation Committee of the Board of Directors authorized the issuance from the 2011 Plan of long term incentive
compensation to employees by granting options for the purchase of 169,000 shares of Common Stock at an exercise price of $1.90
per share. The stock options vest over 4 years and will be completely vested in 2022. Of this amount, options for the purchase
of 75,000 shares of Common Stock were granted to officers of the Company and were disclosed in the Company’s DEF 14A filed
with the Securities and Exchange Commission on April 18, 2018.


 


9.          On
May 3, 2018 the Compensation Committee of the Board of Directors authorized the issuance from the 2011 Plan of long term incentive
compensation to employees by granting options for the purchase of 5,000 shares of Common Stock at an exercise price of $1.85 per
share. These awards vest over the 4 years and will be completely vested in 2022.


 


10.         On
May 3, 2018 the Board of Directors approved annual compensation for the independent directors. As partial compensation for services
provided to the Company during 2018, each independent director was granted 27,027 shares of common stock having a per share value
of $1.85, the closing price of the Company’s common stock on the date of grant. The common stock is earned in quarterly increments
and is issued on the last business day of each calendar quarter. The shares of common stock are issued from the Company's 2011
Equity Incentive Plan. Because the grants were approved in the second quarter, the shares of common stock for both the first and
second quarters of 2018 were issued on June 29, 2018.


 


11.         If
the Company extends the expiration date of the publicly traded warrants to January 25, 2020, it will be required to file a prospectus
supplement to the S-3 registration statement, number 333-208784, and to file a new registration statement that includes a current
prospectus prior to the exercise of the warrants. (See SEC C&DI Securities Act Sections 203.01.)